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Born in West Virginia in 1980, The Neurocritic embarked upon a roadtrip across America at the age of thirteen with his mother. She abandoned him when they reached San Francisco and The Neurocritic descended into a spiral of drug abuse and prostitution. At fifteen, The Neurocritic's psychiatrist encouraged him to start writing as a form of therapy.
by: crdagainSeasonal affective disorder (SAD) is a cyclical depressive disorder that typically recurs every year during the shorter days and longer nights of late fall-early winter. Much of the research on SAD has focused on changes in the photoperiod and the accompanying effects on circadian rhythms during winter. So it might come as a surprise that in Greenland, the suicide rate peaks during the summer months of continuous sun (especially at the highest latitudes). However, the rate of homicides and the sales of beer do not show the same seasonal variation (Björkstén et al., 2009). Why might this be? Most suicides in Greenland are of the impulsive variety and are committed using violent methods. The authors' previous work observed the summer suicide spike (Björkstén et al., 2005), and now they wanted to determine whether homicides show the same seasonal pattern. They reviewed the evidence on serotonin, impulsivity, and violence, and hypothesized that altered serotonin turnover might be a common factor in both violent suicides and violent homicides (reasoning that increased serotonin turnover in spring and summer might enhance impulsiveness and aggression).How was this assessed? Northern Greenland (obviously) shows the greatest seasonal extremes in the amount of light and darkness. The country maintains good statistics, and the Inuit population is considered to be relatively homogeneous. Thus, Björkstén, Kripke, and Bjerregaard (2009) examined computerized records listing the causes of all deaths in Greenland during the time period of 1968-2002. To determine whether alcohol consumption played a role in the rates of suicides and murders, the pattern of beer purchases at a major chain store from July 2005 to June 2006 were used as a proxy ("Detailed sales data are secret for business reasons").The authors note some extremely tragic statistics:The suicide rate in Greenland increased during the 1970’s from a historically very low level to one of the highest levels in the world, 107 per 100,000 person-years in 1990-1994. The increase has been most pronounced among teenagers and young adults. A rapidly increasing suicide rate has been reported from other areas going through radical changes like in Eastern Europe after the fall of communism and among aboriginal people confronted with modern lifestyle.We have previously demonstrated that the vast majority of suicides in West Greenland are violent and peak in the summer when the Northern half of Greenland has constant day-light and the Southern half has extremely long days. Depression has, however, been reported uncommon and the majority of suicides seem impulsive rather than depressive.The overall homicide rate in Greenland has been reported much higher than that of the other Nordic countries. Homicides are almost exclusively impulsive and committed under the influence of alcohol...Continuing in a depressing vein, there were 1351 suicides (80.5 % were men) and 308 homicides during the 35 year period under study.Persons in upper teens and young adults were heavily over-represented among the suicide cases. Median age was 25 years...In 391 out of the 1351 cases (29%), the death certificate included a psychiatric diagnosis. In 214 cases (15.8%), there was a diagnosis of alcoholism or alcohol intoxication; two cases also had a diagnosis of psychosis. In only 52 cases (3.8%), there was a diagnosis of affective disorder, either unspecified or in the depressive state. In 104 cases, there was a diagnosis of psychosis. In addition to the 104 cases (7.7%), there were two with alcoholism and psychosis.However, affective disorders could have been underdiagnosed in the population... we don't really know for sure. What we do know is that violent methods of suicide were used in 95% of all cases (n=1286), with men using violent methods 97% of the time and women 86% of the time (the latter percentage in stark contrast to the general population outside of Greenland). Figure 3a below shows the seasonal variation in all suicide cases. The annual peak occurred on June 11th and the trough in November-January, and the effect of seasonality was significant (p... Read more »
Bjorksten, K., Kripke, D., & Bjerregaard, P. (2009) Accentuation of suicides but not homicides with rising latitudes of Greenland in the sunny months. BMC Psychiatry, 9(1), 20. DOI: 10.1186/1471-244X-9-20
Karen Finley in The Constant State of DesirePhoto by Donna Ann McAdamsIf you are better at exerting self-control by choosing less pleasurable but more healthy options, do you live in a constant state of (suppressed) desire? If you feel like you're always sacrificing and denying yourself what your brain's "valuation system" indicates is worth more, does the craving eventually go away? Or are you more likely to binge in a moment of weakness? Isn't this why most diets fail? Wouldn't it be better to have that candy bar every once in a while? (or else, learn to love cauliflower more than Cadbury)?However, this constant state of desire is not what the mad lib Science paper (Hare et al., 2009) is about. It's not even about dieting at all, despite what the press release says.Caltech Researchers Pinpoint the Mechanisms of Self-Control in the BrainStudy of dieters shows how two brain areas interact in people with the willpower to say no to unhealthy foodsPASADENA, Calif.--When you're on a diet, deciding to skip your favorite calorie-laden foods and eat something healthier takes a whole lot of self-control--an ability that seems to come easier to some of us than others. Now, scientists from the California Institute of Technology (Caltech) have uncovered differences in the brains of people who are able to exercise self-control versus those who find it almost impossible.The key? While everyone uses the same single area of the brain to make these sorts of value-laden decisions, a second brain region modulates the activity of the first region in people with good self-control, allowing them to weigh more abstract factors--healthiness, for example--in addition to basic desires such as taste to make a better overall choice.To start, let's look at the subject selection criteria (Hare et al., Supporting Online Material - PDF):"We recruited two types of subjects: 1) individuals who self-reported being on a diet to lose or maintain weight and 2) individuals who self-reported no current monitoring of their diet. All subjects reported that they enjoyed eating sweets, chocolate, and other “junk food” even though they might be restricting them from their current diet. . . . Subjects were classified as self-controllers (SC) or non-self-controllers (NSC) based on their behavior during the experiment, and not on their self-reports about diet status during the recruiting process."So really, the study isn't about dieting at all,1 because one could be a "self-controller" in the experiment and yet report no dietary restrictions in real life. And actually, the study may not even say much about food choices in the real world, because a participant could say she'd choose the broccoli over the brownie to gain the experimenter's approval, but then go home and eat ice cream for dinner.Back to the subject selection:"Fifty-two subjects participated in the experiment. However 15 subjects did not meet our a priori inclusion criteria based on their behavioral data [they fell into a gray zone]. 37 subjects were included in the analysis. Subjects were divided into two groups based on their behavioral data: successful self-controllers (SC) and non-self-controllers (NSC). The SC group included 19 subjects (14 female ... mean BMI = 24.8 ± 5.2) and the NSC group included 18 subjects (6 female ... mean BMI = 23.2 ± 5.1)."There's a lot more pressure on women to diet and to give the appearance of restraint, and 70% of them were in the SC group. So who knows, it might be true that the female subjects felt more compelled to choose the healthy choice than they would have in real life.Anyway, the experimental design is illustrated below:Fig. 1A. The task proceeded in three parts: taste ratings, health ratings, and decisions. The subjects viewed pictures of 50 different food items and rated them on a 5 point scale for health and taste in two separate blocks. After this, one food item rated as neutral on both dimensions (e.g., crackers, jello) was selected as the reference item, and subjects had to choose between it and another item on each trial."Subjects cared about their choices because they were required to eat the food that they chose in a randomly selected trial at the end of the experiment.2 Note that because subjects did not know which trial would count, their optimal strategy was to treat each decision as if it were the only one that counted. Although this is a binary decision task, subjects were asked to express the strength of their preferences using a five-point scale: Strong No (=choose reference) [to] Strong Yes (=choose shown item)."The participants were sorted into SC and NSC groups according to their behavioral performance during the decision phase. The SC subjects chose food items on the basis of both health and taste, but the NSC group chose on the basis of taste alone. What were the investigators looking for in the fMRI data? They assumed at the outset that the brain's "value assigner" is located in the ventromedial prefrontal cortex3 (vmPFC), and the "self-controller" (in the dorsolateral prefrontal cortex, DLPFC) modulates value signals in vmPFC.For fear of beating a dead horse, I won't get into the fMRI data analysis methods here (5 pages in the supplementary methods) and whether there were any "Voodoo Correlations" (or rather, "Puzzlingly High Correlations" - PDF). But here's a figure from Hare et al. with r=.847.Fig. 2E. Robust... Read more »
Hare, T., Camerer, C., & Rangel, A. (2009) Self-Control in Decision-Making Involves Modulation of the vmPFC Valuation System. Science, 324(5927), 646-648. DOI: 10.1126/science.1168450
A Warm TV Can Drive Away Feelings of Loneliness & RejectionStudies find that illusionary relationships with TV characters can give us real pleasureRelease Date: April 22, 2009BUFFALO, N.Y. -- Not all technology meets human needs, and some technologies provide only the illusion of having met your needs.But new research by psychologists at the University at Buffalo and Miami University, Ohio, indicates that illusionary relationships with the characters and personalities on favorite TV shows can provide people with feelings of belonging, even in the face of low self esteem or after being rejected by friends or family members.The findings are described in four studies published in the current issue of the Journal of Experimental Social Psychology [Derrick et al., 2009].However, after some sleuthing to uncover the classical literature on the topic, I've discovered that Rutherford et al. (1980) described this phenomenon nearly 30 years ago:You're just another face that I know from the TV showI have known you for so very long I feel you like a friendCan't you do anything for me, can I touch you for a whileCan I meet you on another day and we will fly awayTurn It On Again ------Rutherford et al. 1980Derrick et al., 2009 replicated this finding in a series of four experiments, all of which supported the Social Surrogacy Hypothesis, i.e.,...that parasocial relationships provided by television programs can yield the experience of belonging. Specifically, we drew three primary predictions from the Social Surrogacy Hypothesis. If favorite television programs can yield the experience of belonging, we hypothesized that (1) events that typically elicit belongingness needs (e.g., threats to a relationship, a rejection experience) would elicit a desire to experience a favored television program, (2) thinking about a favored television program could buffer against threats to real-world belongingness, and (3) thinking about a favored television program should reduce the accessibility of loneliness related concepts.In Study 1, 701 college students completed the lonely activities scale and the likelihood of feeling lonely scale. These scales were developed for the current study by asking 12 other undergraduates to list non-social activities that people might do when they feel lonely. A final list of 31 activities was given to the larger group, who were asked to rate the items on a scale of 1 (would definitely not do) to 7 (definitely would do). The top six items were:Listen to music – a particular CD/tapeWatch television – a favorite TV programSleepSurf the webEatExerciseParticipants were also asked to rate their likeliness of feeling lonely when doing these activities, on the same 7 point scale. And not surprisingly (since we already know that all of the experiments supported the hypothesis), people felt significantly less lonely when watching TV.Of course, this result was only correlational in nature, so Study 2 manipulated "belongingness needs". Half of the participants were asked to write an essay about a fight with a close other, and the other half were asked to list as many items at home as they could remember. I would have suggested a better neutral essay-writing condition than the residental list, along with a condition to deliberately reduce "belongingness needs" (like an essay about an enjoyable shared experience with a close other). But then again, I'm not a social psychologist, so what do I know?After the first writing exercise, subjects were asked to write another essay about watching either a favorite show, or whatever was on at the time.Participants in the Favored condition wrote about a time they watched their favorite television program, describing it in as much detail as possible. Participants in the Control condition wrote about a time when they had watched “whatever was on” television, describing it in as much detail as possible. Participants were asked to describe as much as they could about the content of the program and their experience watching it. Length of time writing this Parasocial essay served as the primary dependent measure.Lo and behold, the predicted Belongingness Needs × Parasocial Essay interaction was obtained:Fig. 1 (Derrick et al., 2009). Length of time spent writing television essay as a function of social needs condition and type of television program.Study 3 was nearly identical to Study 2, except the Parasocial Essay component was limited to 6 min, and the dependent measures were self-esteem, mood, and feelings of rejection. Again, the predicted Belongingness Needs × Parasocial Essay interactions were obtained for state self-esteem, mood, and a trend for feelings of rejection.Now the authors need to extend these findings to actually watching a favorite vs. a random TV show, instead of just thinking about watching.See also:TV Relieves LonelinessDoes Your TV Give You the Warm Fuzzies?ReferencesDerrick, J., Gabriel, S., & Hugenberg, K. (2009). Social surrogacy: How favored television programs provide the experience of belonging. Journal of Experimental Social Psychology, 45 (2), 352-362. DOI: 10.1016/j.jesp.2008.12.003Rutherford M, Collins P, Banks T. (1980). Turn It On Again. Duke.All I need is a TV show, that and the radioDown on my luck again, down on my luck againI can show you I can show you some of the people in my lifeI can show you I can show you some of the people in my lifeIt's driving me mad just another way of passing the dayI, I get so lonely when she's not thereTurn It On Again ------Rutherford et al. 1980... Read more »
Derrick, J., Gabriel, S., & Hugenberg, K. (2009) Social surrogacy: How favored television programs provide the experience of belonging. Journal of Experimental Social Psychology, 45(2), 352-362. DOI: 10.1016/j.jesp.2008.12.003
In light of all the sensationalistic press coverage about a journal article that wasn't publicly available last week, it's worth taking a moment to look at the actual experiment. Of course, the savvy skeptics know by now that the paper in question (Immordino-Yang et al., 2009) has absolutely nothing to do with Twitter (see Recommended Reading below for a recap). Instead, the authors conducted a neuroimaging study to examine the brain's response to stories designed to elicit the emotions of admiration and compassion. To do this, the participants (n=13) first watched a series of mini-documentary narratives about real people (who were not celebrities). Each of the 50 narratives was 60-90 sec long, and incorporated audio, video, and still images to convey stories categorized as:1. Admiration for virtue (AV), which involved people performing highly virtuous, morally admirable acts. The narratives emphasized the virtuous and morally admirable nature of the protagonist, such as dedication to an important cause despite difficult obstacles, and did not include displays of notable skill.2. Admiration for skill (AS), which involved people adeptly performing rare and difficult feats, e.g., an athletic or musical performance, with both physical and cognitive components. No physically or socially painful acts were shown, and the skillful feats, although amazing, did not imply a virtuous protagonist or reveal a virtuous act.3. Compassion for social pain (CSP), which involved people in states of grief, despair, social rejection, or other difficult psychological circumstances. No physical pain was evident in these narratives, and the troubling circumstances were discerned from the descriptions, rather than being apparent in the images shown.4. Compassion for physical pain (CPP), which involved people sustaining a physical injury. The injuries were caused by sports and other mishaps and had no moral or social implications. The injuries were not the result of malevolence, and the participants were reassured that the injuries had no long-term implications....5. Control narratives, which involved comparable living, mentally competent people engaged in or discussing how they felt about typical activities under commonplace social circumstances. These circumstances were engaging but not emotion provoking.After each of the narratives, the subjects were asked to discuss how they felt about the protagonist's situation. This part of the study took 2 hrs, and was conducted outside the scanner. For the fMRI portion of the protocol, 5 sec recaps of all 50 scenarios were presented, and the task was to:induce in themselves for each story, as strongly as possible, a similar emotional state to the one they had experienced during the preparation session and to push a button to indicate the strength of the emotion they achieved in the scanner (from 1 to 4...). Participants were asked to report candidly on the strength of their current feelings in the scanner, rather than on the strength of feeling they remembered from the preparation session.OK, so the subjects were first asked to remember how they felt 2 hrs ago, then try to duplicate that feeling, and then report on how they feel now (rather than before). So there's a memory component and a decision component (i.e., to not confuse past feelings with the present). Each trial was sorted post hoc on the strength of the reported emotion, and only the effective trials were included in the analysis.The comparisons of interest were pain (compassion) vs. non-pain (admiration), and emotional responses to other peoples’ social/psychological conditions (AV, CSP) vs. to their physical conditions (AS, CPP). One of the first issues discussed is the recruitment of homeostatic mechanisms when experiencing these social emotions:It is well known that basic emotions such as fear, sadness, and happiness and limited social emotions such as moral indignation engage neural systems concerned with sensing and regulating body function with varying patterns, and it has been hypothesized that among those systems, the insula plays an especially prominent role. It is also known that engagement of social emotions and the consequent feeling for another’s social/psychological situation are described by poets and lay people alike in visceral and bodily terms and in terms of their heightening effect on one’s own self-awareness or consciousness.Basically, people may have visceral responses to the circumstances of others. How do these responses differ across physical vs. psychological situations? For example, admiring a gymnast's skill on the balance beam vs. admiring a student's charity work with Habitat for Humanity? Or feeling compassion for a single mother who loses her job vs. feeling compassion for one who sprains her ankle? Although it's not mentioned in the paper, this idea draws on Antonio Damasio's somatic marker hypothesis (e.g., Damasio, 1996). Perhaps this omission occurred because two of the main regions implicated -- the ventromedial prefrontal cortex (VMPFC) and the amygdala -- were not discussed in the paper [however VMPFC is difficult to image using fMRI because of susceptibility artifacts]. The somatic marker hypothesis is succinctly described by the title of one of Damasio's books: The Feeling of What Happens: Body and Emotion in the Making of Consciousness (1999).Other components in the somatic marker circuit include the insular cortex, a region implicated in interoceptive awareness of bodily states (Craig, 2009), and somatosensory cortices responsive to external stimuli. Because activity in the anterior insula features primarily in the Twitter-warped distortion of the story, I'll start here with the authors' third hypothesis:3. that activation in the anterior insula would peak and dissipate more quickly for CPP than for CSP or varieties of admiration.In a way, this is a trivial prediction, because one can evaluate the sprained ankle narrative more quickly than the job loss scenario. In fact, I will argue below that simple behavioral response time might be a more precise measure of how long it takes to generate the emotion in question than is the hemodynamic response (blood flow changes, measured by the BOLD signal in fMRI) in the insular cortex. One reason for this is because of the significant delay (5-6 sec at least) between initial neural firing and the peak of the hemodynamic response, which is estimated using a procedure that is not trivial for something as complex as an emotional response (for a more detailed discussion of this issue, I recommend this PPT file from Jodi Culham's excellent fMRI 4 Newbies site).Let's start with a simpler example. The figure below shows the averaged hemodynamic response function (HRF) in the primary visual cortex to a series of flashes. The HRF peaks at ~5 sec after the flash, whereas neurons in primary visual cortex fire within 50 msec and drop off shortly thereafter. Thus, the hemodynamic response to even a simple sensory stimulus lags behind neuronal firing by 5 sec.Fig. 2 (Calhoun et al., 1998). Time courses from four regions in the calcarine cortex (Pl-P4) and the averaged response (CIRQ). Amplitude units are normalized to a maximum of one and a baseline of zero.The next example shows the HRFs in occipital regions and the insula while subjects viewed rotating objects. The precise details aren't important here, but note the peak latency for the HRF in the insula is around 6-8 sec, with the later peak for novel objects (compared to repeated objects).Fig 2C (Weigelt et al., 2007). Event-related deconvolved BOLD fMRI responses (GLM parameter estimates averaged across trials and subjects for all voxels in each ROI) reported against time for each of the experimental conditions.That brings us back to Immordino-Yang et al. and the emotional narratives. In the figure below, note that the HRF time course does peak earlier for the CPP condition compared to the others, as predicted. However, the CSP condition rises at the same time, albeit with a later (very broad) peak.Fig. 3 (Immordino-Yang et al., 2009). Event-related averages for the time courses of admiration and compassion in the anterior insula, with standard errors. Units are percentage change in BOLD signal and time in seconds; time courses are not corrected for hemodynamic delay. For display purposes, BOLD data have been linearly interpolated to 1-s resolution. The volume of interest is displayed in pink. Conditions: AV (green): admiration for virtue; AS (yellow): admiration for skill; CSP (blue): compassion for social pain; CPP (red): compassion for physical pain. Note the rapid rise and dissipation of CPP versus the slower and more sustained rise of CSP, AV, and AS.It's critical to note that the onset of a felt emotion is not as easy to determine as the onset of a visual object. Although more detailed methods are in the Supplementary Materials not available as of this writing, it seems that respiration and heart rate data were obtained in 7 of the 13 subjects to help with this. I would say these psychophysiological responses, in concert with the participants' own reaction times for rating their subjective responses, would provide a more accurate measure of how long it takes to feel an emotion than the fMRI data. It's hard to know what an insular HRF of 6 sec vs. 10 sec means when watching a fast-paced movie or reading the CNN news crawl or yes, spending too much time on Twitter. Nonetheless, on the basis of these imprecise latency measures, the authors speculate:If replicated, this finding could have important implications for the role of culture and education in the development and operation of social and moral systems; in order for emotions about the psychological situations of others to be induced and experienced, additional time may be needed for the introspective processing of culturally shaped social knowledge. The rapidity and parallel processing of attention-requiring information, which hallmark the digital age, might reduce the frequency of full experience of such emotions, with potentially negative consequences.And there's your "Twitter is evil" angle.I'll leave you with this final thought: where's the line between admiration and envy, between compassion and schadenfreude? There actually is a recent paper on the Neural Correlates of Envy and Schadenfreude (Takahashi et al., 2009), and for now I'll refer you to this nice summary in Pure Pedantry.Recommended Twitter Reading:Social media threats hyped by science reporting, not science (Ars Technica)Experts say new scientific evidence helpfully justifies massive pre-existing moral prejudice. (Bad Science)For the last time: that "Twitter is Evil" paper is not about Twitter! (Bioephemera)Is Twitter evil? (Cosmic Log at MSNBC - despite the ridiculous headline, it's one of the few popular science articles to talk about the actual study... it even included a figure from the paper)The Neurology of Twitter (The Neurocritic proposes an actual fMRI study of Twitter, complete with predicted results)The Neurology of Twitter, Part 2 (Yet another recap of the media circus, with a time line of certain events)ReferencesCraig AD. How do you feel--now? The anterior insula and human awareness. (2009). Nat Rev Neurosci. 10:59-70.Damasio AR. (1996). The somatic marker hypothesis and the possible functions of the prefrontal cortex. Philos Trans R Soc Lond B Biol Sci. 351:1413-20.Mary Helen Immordino-Yang, Andrea McColl, Hanna Damasio, and Antonio Damasio. (2009). Neural correlates of admiration and compassion. Proceedings of the National Academy of Sciences.... Read more »
Mary Helen Immordino-Yang, Andrea McColl, Hanna Damasio, and Antonio Damasio. (2009) Neural correlates of admiration and compassion. Proceedings of the National Academy of Sciences.
Voodoo no more!The paper everyone loves (or loves to hate) has a new name.1 Through a number of channels [The Chronicle of Higher Education via @vaughanbell, Ed Vul's website, and Neuroskeptic], The Neurocritic has learned that the "Voodoo Correlations" have been downgraded to mere "Puzzlingly High Correlations." The field of social neuroscience has been spared as well, because the full title of the paper is now "Puzzlingly High Correlations in fMRI Studies of Emotion, Personality, and Social Cognition" (PDF).By now, most neuroimagers and cognitive neuroscientists have heard about that controversial (some would say inflammatory) paper by Ed Vul and colleagues, summarized in this post.2 In the article, Vul et al. claimed that over half of the fMRI studies that were surveyed used faulty statistical techniques to analyze their data:...using a strategy that computes separate correlations for individual voxels, and reports means of just the subset of voxels exceeding chosen thresholds. We show how this non-independent analysis grossly inflates correlations, while yielding reassuring-looking scattergrams. This analysis technique was used to obtain the vast majority of the implausibly high correlations in our survey sample.Needless to say, authors of the criticized papers were not pleased. Two rebuttals were released online shortly thereafter: one by Jabbi et al. (PDF) -- here's the response to that rebuttal -- and an invited reply by Lieberman et al. (PDF).That was back in January, after the manuscript had been accepted for publication by Perspectives on Psychological Science in late December 2008. Now [finally], the paper has been officially published in the May 2009 issue of the journal, with an introduction (PDF) by Ed Diener, the editor. Also included are six Commentaries by assorted authors and a Reply to the Commentaries by Vul et al. (PDF).I haven't had time to read all the commentaries and rebuttals yet, but the Editor's Introduction is worth a quick mention for the issues it raises about peer review and publication in these modern times.PREPUBLICATION DISSEMINATIONAs soon as I accepted the Vul et al. article, I heard from researchers about it. People around the globe saw the article on the Internet, and replies soon appeared as well. Although my plan was to publish the article with commentary, the appearance of the article on the Internet meant that researchers read the article without the accompanying commentaries and replies that I had planned to publish with it.In some fields such as economics, it is standard practice to widely disseminate articles before they are published, whereas in much of psychology this has been discouraged. An argument in favor of dissemination is that it speeds scientific communication in a fast-paced world where journal publication is often woefully slow. An argument against dissemination of articles before publication is that readers do not have the opportunity to simultaneously see commentary and replies. ... In the Internet age, the issue of prepublication distribution becomes all the more important because an article can reach thousands of readers in a few hours. Given the ability of the Internet to communicate so broadly and quickly, we need greater discussion of this issue.Bloggers have discussed this specific issue months ago. For example, as noted in Mind Hacks,The paper was accepted by a peer-reviewed journal before it was released to the public. The idea that something actually has to appear in print before anyone is allowed to discuss it seems to be a little outdated (in fact, was this ever the case?).And The Neurocritic opined that...[The aggrieved authors] are not keeping up with the way that scientific discourse is evolving. Citing "in press" articles in the normal academic channels is a frequent event; why should bloggers, some of whom are read more widely than the authors' original papers, refrain from such a practice? Is it the "read more widely" part?...and in The Voodoo of Peer Review asked:Are blogs good or bad for the enterprise of scientific peer review? At present, the system relies on anonymous referees to provide "unbiased" opinions of a paper's (or grant's) merits. For today, the discussion will focus on peer review of papers in scientific journals....[An] article [in Seed Magazine] begins:Few endeavors have been affected more by the tools and evolution of the internet than science publishing. Thousands of journals are available online, and an increasing number of science bloggers are acting as translators, often using lay language to convey complex findings previously read only by fellow experts within a discipline. Now, in the wake of a new paper challenging the methodology of a young field, there is a case study for how the internet is changing the way science itself is conducted.Really? Maybe that's true for Biological and Social Sciences, but certainly not for Physics, Mathematics, Computer Science, Quantitative Biology, Quantitative Finance and Statistics (see arXiv.org)...Diener then raises the point that online bloggers and commenters may be discussing various versions of the manuscript:Another problem that has arisen in terms of Internet “publication” of the article and the Internet replies is that different individuals will have read different versions of the article. A single reader is unlikely to read more than one version of the article and will therefore often not see later corrections and changes. Furthermore, the commentaries are to some extent replies to different versions of the article and therefore might not be entirely on-target for the final version. This makes it difficult to fully understand the arguments because comments and replies might not be to the most current versions of articles, and it is impossible to fully correct this because the back-and-forth of revisions could continue indefinitely.So there's never a final version of the article because revisions continue indefinitely?? Or are the accepted and final versions of the manuscript so radically different [why, I might ask] that a discussion of the initially accepted version is misleading? Or instead, is it the online commenters who are "revising" the article ad infinitum? Will Diener's editorial be clarified in a future edition, thus rendering moot my confusion in this particular post?At any rate, Diener also discusses ethical issues surrounding the questionnaire that Vul et al. distributed to the authors. Some believed they were unwitting participants in Human Subjects research and did not give their informed consent (Diener disagreed). Not surprisingly, the "article tone" was another source of contention, and here Diener agreed to change the original "Voodoo" title. Finally, some of the aggrieved authors disputed the accuracy of the entire paper, suggesting that some (if not all) of their research was incorrectly classified. But in the end, the editor defers to the readers, who will judge the article and comments and form their own opinions.I believe that the debate can itself stimulate useful discussions about scientific practices and communication. Further discussion of the issues should now take place in journals that are focused on imaging and neuroscience, so that the readers there can judge and benefit from the ensuing discussions.I believe that further discussion of the issues can also take place on blogs that are focused on imaging and neuroscience. So feel free to discuss at length. Leave your questions and observations in the comments section of this post!Footnotes1 See The Voodoo of Peer Review for a preview of this issue.2 You can also read a quick overview at Scan Scandal Hits Social Neuroscience, and more in-depth commentary in the post Voodoo Schadenfreude. And a comprehensive list of links about the the paper is located here.Ed Diener (2009). Editor's Introduction to Vul et al. (2009) and Comments. Perspectives on Psychological Science, 4 (3).Complete List of References (from PERSPECTIVES ON PSYCHOLOGICAL SCIENCE, Vol. 4, Issue No. 3 · May 2009)Editor's Introduction to Vul et al. (2009) and CommentsEd Diener Puzzlingly High Correlations in fMRI Studies of Emotion, Personality, and Social CognitionEdward Vul, Christine Harris, Piotr Winkielman, and Harold Pashler Commentary on Vul et al.'s (2009) "Puzzlingly High Correlations in fMRI Studies of Emotion, Personality, and Social Cognition"Thomas E. Nichols and Jean-Baptist Poline Big Correlations in Little Studies: Inflated fMRI Correlations Reflect Low Statistical Power--Commentary on Vul et al. (2009)Tal Yarkoni Correlations in Social Neuroscience Aren't Voodoo: Commentary on Vul et al. (2009) Matthew D. Lieberman, Elliot T. Berkman, and Tor D. Wager Discussion of "Puzzlingly High Correlations in fMRI Studies of Emotion, Personality, and Social Cognition" by Vul et al. (2009)Nicole A. Lazar Correlations and Multiple Comparisons in Functional Imaging: A Statistical Perspective (Commentary on Vul et al., 2009)Martin A. Lindquist and Andrew Gelman Understanding the Mind by Measuring the Brain: Lessons From Measuring Behavior (Commentary on Vul et al., 2009)Lisa Feldman Barrett Reply to Comments on "Puzzlingly High Correlations in fMRI Studies of Emotion, Personality, and Social Cognition"Edward Vul, Christine Harris, Piotr Winkielman, and Harold Pashler... Read more »
Ed Diener. (2009) Editor's Introduction to Vul et al. (2009) and Comments. Perspectives on Psychological Science, 4(3).
Heterotopagnosia is an unusual neurological syndrome, as described below by Laurent Cleret de Langavant and colleagues:Heterotopagnosia is the acquired inability of brain-lesioned patients to point at someone else's body parts when prompted. The cognitive basis of this disorder is unclear. It might result from a biological function deficit critical for communication in human beings; alternatively, it could result from the disruption of a body representation. Here, we report three patients with heterotopagnosia following a recent left parieto-occipital stroke and a previous insular lesion. The patients were tested on their ability to name, point out and grasp several targets including body parts (own, real others’ and figurative others’). Language, visuo-spatial deficits or any confounding neuropsychological disorders were controlled for. We found that the patients erroneously pointed to their own body parts when asked to point at someone else's. Strikingly, their ability to grasp someone else's body parts was largely unimpaired. The dissociation between their grasping and communicative pointing abilities supports the hypothesis that heterotopagnosia is a disorder of communicative function conveyed by pointing but not by grasping. In addition, pointing performance in our patients varied according to the target: the more similar the target was to a real person, the worse the patients’ pointing performance. We suggest that communicative pointing might require a specific representation of the addressee's body and point of view, a heterocentric representation. In the patients described here this phenomenon resulted from a combined insulo-parietal lesion, which may explain why, in contrast to other patients described previously, the heterotopagnosia was long-lasting.The area of maximum lesion overlap was a region in the left parieto-occipital cortex, as shown in this drawing depicting the area of damage shared by all three patients.Fig. 3. (Cleret de Langavant et al., 2009). The overlap of the left parieto-occipital junction lesion (Brodmann area 19), common to all three patients. Note that there is no overlap within the insular region for the three patients since COG has a left insular lesion and ROM and BEG a right one.What can explain this unusual disorder? First, the authors ruled out several possibilities:The features of heterotopagnosia set this pointing disorder apart from any other known neurological disorder. The patients’ preserved performance in grasping and touching body parts rules out any causal visual or spatial impairment based on the size, type, complexity or componential analysis of the target. Likewise, a language deficit cannot account for the patients’ performance in pointing. The spared ability of patients in naming body parts they cannot point to, their use of possessive and demonstrative grammatical indices and their perfect understanding of pointing exclude a category-specific lexical impairment.Instead, they suggested the patients exhibited a deficit selective for another person's body, problems with self-referencing behavior, and a dissociation between impaired pointing versus intact grasping/touching. The authors concluded by asking......why is pointing interesting if its impairment has no consequences in daily life? We suggest that pointing is a residual function that is fundamental in infant development. It marks the construction of the three-way relationship of communication (self-addressee-object or I-you-he/she/it), as a keystone for the development of language and theory of mind. In adults, its impairment is compensated by abilities that have integrated and supplanted it, leaving intact relationships with others (e.g. verbal communication and knowledge concerning others).ReferenceCleret de Langavant, L., Trinkler, I., Cesaro, P., & Bachoud-Lévi, A. (2009). Heterotopagnosia: When I point at parts of your body. Neuropsychologia DOI: 10.1016/j.neuropsychologia.2009.02.016... Read more »
Cleret de Langavant, L., Trinkler, I., Cesaro, P., & Bachoud-Lévi, A. (2009) Heterotopagnosia: When I point at parts of your body. Neuropsychologia. DOI: 10.1016/j.neuropsychologia.2009.02.016
And the ones that mother gives you Don't do anything at all Go ask Alice When she's ten feet tallWhite Rabbit ---Jefferson AirplaneNo, we're not really discussing hallucinogenic drugs today (despite the psychedelic reference). The real question for today is this: Does the wakefulness drug modafinil (Provigil) lessen the weight gain caused by atypical antipsychotics? Not really (Roerig et al., 2009), despite what the Elsevier press release tells us:Combating Weight Gain Caused by Antipsychotic TreatmentsPhiladelphia, PA, March 26, 2009 – Antipsychotic drugs, such as olanzapine (Zyprexa), risperidone (Risperdal), and quetiapine (Seroquel) are commonly used to treat psychotic disorders like schizophrenia, but also bipolar disorder and even behavioral problems related to dementia. Unfortunately, the weight gain commonly experienced with antipsychotic treatment is an important side effect for many patients, and causes many patients to discontinue their use leading to even further problems. Biological Psychiatry, in its April 1st issue, is now publishing a new study that has evaluated an add-on treatment to potentially reduce treatment-associated weight gain.In a randomized, double-blind, placebo-controlled trial, Dr. James Roerig and colleagues evaluated the effect of modafinil on olanzapine-associated weight gain in normal volunteer subjects. Modafinil is a drug currently used to increase wakefulness in individuals with sleep disorders, such as narcolepsy. All of the subjects received olanzapine, and half also received modafinil treatment while the other half instead received placebo. After three weeks, although the body mass index was increased in both groups, those receiving olanzapine/placebo showed significantly greater weight increase than those receiving olanzapine/modafinil.The April 1st issue, hmm... You'll notice the study was conducted in normal volunteer participants and only for a 3 week period. What you didn't see in the press release is that during the 3 week period, 10 of the 50 original subjects withdrew from the trial (2 in modafinil + olanzapine group, and 8 in placebo + olanzapine group).Zyprexa has rightfully received some bad press lately (so has Seroquel, but that story is more colorful). Although olanzapine is quite effective in treating schizophrenia and bipolar mania, it is notorious for causing very large weight gains in those taking it ("you'll gain five pounds just by filling the prescription" or 1.5 pounds per month according to a recent meta-analysis by Parsons et al., 2009). A 1999 article by Allison et al. was even worse: a gain of nearly a pound per week for 10 weeks (4.45 kg total!).1 One mechanism for this might involve increases in ghrelin, a hormone that stimulates appetite (see Brain Health Hacks).Enter modafinil, which has been touted as a cognitive enhancing drug taken by some shifty academics. A recent paper on the Effects of Modafinil on Dopamine and Dopamine Transporters in the Male Human Brain (Volkow et al., 2009) caused some to ask whether modafinil might be addictive. But the answer is that it's probably not, even though it increases the level of dopamine (the "reward" neurotransmitter) by blocking the dopamine transporter. In addition to its effects on dopamine, modafinil also affects the norepinephrine neurotransmitter system, as shown in a technically difficult neuroimaging study (Minzenberg et al., 2008) of the human locus coeruleus, a small nucleus in the brainstem. Also on the plus side for modafinil is its potential usefulness in psychiatric practice: for improving attention and executive control function in schizophrenia (Morein-Zamir et al., 2007), and as an add-on medication in treating bipolar depression (Belmaker, 2007).But the paper of today (Roerig et al., 2009) did none of that, instead enrolling healthy control participants2 and seeing whether modafinil attenuated the olanzapine-induced weight gain. A previous experiment by this group (Roerig et al., 2005) observed a 5 lb. increase over a 2 week period, significantly greater than both risperadone and placebo (Table 2). The number of calories consumed was numerically greater, but did not reach significance.Table 2 (Roerig et al., 2005). Weight Change (in kilograms). Calorie Change (in kilocalories).What about the current study?In the completer analysis, the primary outcome variable, BMI [body mass index] change from baseline, was significantly different between groups with the olanzapine/placebo group experiencing a greater increase in BMI than the olanzapine/modafinil group (.89 + .59 vs. .47 + .50 kg/m2, p... Read more »
Roerig, J., Steffen, K., Mitchell, J., Crosby, R., & Gosnell, B. (2009) An Exploration of the Effect of Modafinil on Olanzapine Associated Weight Gain in Normal Human Subjects. Biological Psychiatry, 65(7), 607-613. DOI: 10.1016/j.biopsych.2008.10.037
Lie to Me - Season 1 - "Moral Waiver" - Monica Raymund as Ria Torrescourtesy Adam Taylor/FoxLie detection is all the rage with the new TV show based on Paul Ekman's work1 that uses "microexpressions" to detect deception.The use of brain imaging technologies as lie detectors, and the admissibility of data obtained in this fashion as evidence in a court of law, has a high media profile as well - most recently (and notoriously) because of a juvenile-sex-abuse case in San Diego, recounted by Wired Science. The Stanford Center for Law & the Biosciences Blog has sounded the alarm in their post, No Lie MRI being offered as evidence in court:The case is a child protection hearing being conducted in the juvenile court. In brief, and because the details of the case are sealed and of a sensitive nature, the issue is whether a minor has suffered sexual abuse at the hands of a custodial parent and should remain removed from the home. The parent has contracted No Lie MRI and apparently undergone a brain scan... The defense plans to claim the fMRI-based lie detection (or “truth verification”) technology is accurate and generally accepted within the relevant scientific community in part by narrowly defining the relevant community as only those who research and develop fMRI-based lie detection.The Neurocritic weighed in on the overblown nature of these claims three years ago, with Brain Scans and Lie Detection: True or False?, Would I Lie to You?, and More Lies... Damn Lies... But even better, check out the excellent Deception Blog for an updated overview of the field.Given the high cost and dubious accuracy of fMRI technologies -- as well as the questionable accuracy of older EEG and polygraph methods -- there has been some interest in developing faster, easier, more reliable lie detection methods. Ian Sample at the Guardian's Science Blog went with this futuristic headline about the potential use of pupillometry as a routine security screening measure:Homeland Security seeks Bladerunner-style lie detectorDo our eyes betray us when we lie? The US government hopes to find out. . .Under the Small Business Innovation Research programme, the department has asked tech companies to bid for contracts to kick-start research in the area. Such a system, if it works, would undoubtedly be useful at airports and other high-security points.Here's the original SBIR solicitation for applications, which were due in February 2008:TITLE: Assess Ability to use Eye Tracking and Pupil Dilation to Determine Intent to DeceiveDESCRIPTION: Recent government sponsored research is working to produce a new line of flexible physiological and behavioral sensor technologies that are to be available for homeland security applications. These sensors, which must be non-invasive in nature and protect the privacy of the individual(s) involved, will be used to support human centered/behavioral screening processes in a variety of high and low volume venues. Security screening is conducted to evaluate the risk of individuals entering transportation and other critical infrastructure and requires efficient, rapid and accurate examination of a person. Persons involved in or planning to be involved in possible malicious or deceitful acts will show various behavioral or physiological abnormalities. Much of the technology and publications to date have focused on detection of guilty individuals using electrodermal measures. Research into other psychophysiological measures or the mechanisms underlying deception is still in its early stages. Early research has shown that pupil size varies with changes in a person's cognitive processing load. Current but unproven studies suggest that a cognitive decision to deceive or practice deception will result in a increased pupil size due to the greater cognitive processing required in comparison to truthful recall. An assessment study to determine the correlation between Pupillometry (dilation and contraction of the pupil relative to observed stimulus or emotion) and intent to deceive is required.For the ultimate in low-cost methods for lie detection, computerized reaction time tasks take the cake. An article about one of these appeared last year in Psychological Science (Sartori et al., 2008). The task they used is a variant of the Implicit Association Test (IAT) franchise that pits competing response tendencies against each other. Without getting into a lengthy discussion of the IAT, and the debates between its proponents and detractors,2 the autobiographical IAT (aIAT) employed by Sartori et al. ......allows one to evaluate which of two contrasting autobiographical events is true for a given individual. This is accomplished by requiring the respondent to complete two critical blocks of categorization trials, each of which pairs a different potentially autobiographical event with true events. Because pairing of a truly autobiographical event with true events should facilitate responses, the specific pattern of response times (RTs) in the two blocks indicates which autobiographical event is true and which is false.The participants saw different types of sentences and had to classify them as true/false or guilty/innocent. Examples of the different stimuli are listed below.adapted from Table 2 (Sartori et al., 2008).The real trick was in the way these sentence types were matched to response keys. In a series of five blocks of trials, the subjects were told to respond to each sentence as rapidly as possible. Across five experiments (each of which had a different kind of "guilty knowledge"), the order was Block 1: logical discrimination (true/false) - Block 2: initial autobiographical information (guilty/innocent) - Block 3: initial double categorization (false/innocent and true/guilty) - Block 4: reversed autobiographical discrimination (false/true) - Block 5: reversed double categorization (true/innocent and false/guilty). The order of the critical blocks 3 and 5 was counterbalanced across participants (as was the order of 2 and 4, which counterbalanced the response mapping for autobiographical trials accordingly). The key measure was the comparison between RTs to the double categorization trials in Blocks 3 and 5 -- innocent participants were expected to be slower on the "conflict" trials in which true/guilty and false/innocent were matched to the same response key, while guilty participants (who always denied their crimes) were expected to show the opposite pattern, which would reveal they were lying about their innocence.For the mock crime of stealing a CD for example, the results looked like this for the pairings of true/guilty and true/innocent:Fig. 1C (Sartori et al., 2008). For Experiment 2, results are shown for the critical block associating true sentences with guilty sentences and for the critical block associating true sentences with innocent sentences.Because the tests were able to discriminate between true and false events with 91% accuracy, the authors concluded that "the aIAT is an accurate method of detecting concealed knowledge that outperforms currently available lie-detection techniques." However, a brand new paper by Verschuere et al. (2009) has demonstrated that it's easy to fake your results in this aIAT! Oops. What Verschurere and colleagues did was provide the participants with instructions on how to beat the test. Before performing the aIAT a second time, they were told to slow down their responses in the true/guilty mapping condition. And the results for the faking version of the aIAT classified the majority of guilty liars as innocent. Imposing a response deadline, so the subjects had to respond within 1200 msec, did not alter the results.So there you have it. An extremely easy method for faking your results on the aIAT. In the past, The Neurocritic has taken the Human or Alien? test and the Dead or Alive? test. Turns out I'm neither human nor alien, and neither dead nor alive. Read those posts, and then try the tests yourselves.Footnotes1 However, as noted recently by World of Psychology, a paper by Bond (2008) questioned whether Ekman et al. (1991, 1999) omitted data unfavorable to their previously reported lie detection success rate of 73% in some federal agents. 2 The sadly defunct blog Mixing Memory was particularly critical of the IAT:The IAT isn't the only test of implicit "attitudes." . . . However, the IAT is the most popular, and has received a great deal of attention in the popular press, due in large part to a public relations campaign by its authors and the NSF and NIMH. In my mind, giving the IAT so much publicity is the most irresponsible thing I've seen in psychology since I began studying it... While the IAT has been publicized (by its authors!) as a measure of implicit attitudes, and even more, as a measure of implicit prejudice, there is no real evidence that it measures attitudes, much less prejudices. In fact, it's not at all clear what it measures, though the fact that its psychometric properties are pretty well defined at least implies that it measures something. On top of that, the IAT (like all of the other implicit tests) has serious methodological flaws that are currently being discussed in the literature. It's just irresponsible to publicize work, and claim that it does something very particular, when the work is still in the early stages and it's not at all clear what it's actually doing (read paper, or this one, for discussions of some of the problems with the IAT and other measures, including whether they actually measure "attitudes").ReferencesSartori, G., Agosta, S., Zogmaister, C., Ferrara, S.D., & Castiello, U. (2008). How to accurately assess autobiographical events. Psychological Science 19:772–780.Verschuere, B., Prati, V., & Houwer, J. (2009). Cheating the Lie Detector: Faking in the Autobiographical Implicit Association Test. Psychological Science DOI: 10.1111/j.1467-9280.2009.02308.x.Lie to Me - Season 1 - "Moral Waiver" - Kelli Williams as Gillian Foster and Tim Roth as Cal Lightmancourtesy Adam Taylor/Fox... Read more »
Verschuere, B., Prati, V., & Houwer, J. (2009) Cheating the Lie Detector: Faking in the Autobiographical Implicit Association Test. Psychological Science. DOI: 10.1111/j.1467-9280.2009.02308.x
Verschuere, B., Prati, V., & Houwer, J. (2009) Cheating the Lie Detector: Faking in the Autobiographical Implicit Association Test. Psychological Science. DOI: 10.1111/j.1467-9280.2009.02308.x
From the authors who first brought you "sexual sweat" (Zhou & Chen, 2008)...Be afraid... be very afraid and prepare yourself for the sequel: "FEARFUL SWEAT" (Zhou & Chen, 2009)!!!In case you didn't know that "sexual sweat" (collected from men watching porn) differs from ordinary sweat, the results of an fMRI experiment suggested that the orbitofrontal cortex and the fusiform region in 20 female participants responded differently when smelling the two substances (Zhou & Chen, 2008). However, we don't know anything specific about the unique chemical composition of sweat obtained from sexually aroused men, and why it resulted in differential brain activity in women who could not identify the odor as "sweaty/human" (see When I Get That Feeling, I Need Sexual Sweating).Nonetheless, in the present study Zhou and Chen (2009) wanted to determine the effects of another putative chemosensory signal on the perception of emotional expressions in faces. Specifically, as they explain below......we conducted two experiments focused on the effect of a fear-related chemosignal (sweat collected from donors viewing horror videos) in an emotion-identification task. We used the same type of olfactory stimuli (emotional sweat collected on gauze pads and gauze pads with no sweat) throughout, but varied the effectiveness of the visual input by varying the ambiguity of the facial emotions (from somewhat happy to ambiguous to somewhat fearful). Our manipulation of ambiguity was achieved through morphing between happy and fearful faces [as shown in Fig. 1a].Fig. 1a (Zhou & Chen, 2009). Examples of the morphed faces of two actors. For each actor, we selected seven morphs, ranging from somewhat happy to somewhat fearful. These faces were judged to be fearful 20% to 80% of the time in our pilot experiment, in the absence of any olfactory stimuli. Specifically, the Level 4 morph for each actor was the most ambiguous, judged to be fearful in the pilot study 45% to 55% of the time. And what about the olfactory stimuli obtained from the male sweat donors?On the day of each session, they wore next to their skin a new T-shirt (provided by the experimenter), to prevent odor contamination by their regular clothes. During each session, they kept a 4- x 4-in. pad (rayon-polyester blend for maximum absorbance) under each armpit while they watched each of three 20-min video segments intended to produce the emotions of fear (horror movies), happiness (slapstick comedies), and neutrality, respectively. Different videos were shown in each session. During the videos, participants’ heart rate was recorded... After watching each video, the donors rated how angry, fearful, happy, neutral, and sad they felt during the video, using a 100-mm visual analog scale. From each donor, we selected the pads worn during the 20-min videos that elicited the highest level of self-reported happy feelings and the highest level of self-reported fearful feelings. So the 48 young female subjects (mean age 19.6 years) viewed the various faces while exposed to different olfactory stimuli, and decided whether they were happy or fearful. Results indicated that on average they were significantly more likely to identify the most ambiguous morph as fearful when smelling the fearful sweat relative to the control condition (which, unfortunately, was a rayon-polyester pad with no sweat). Although the likelihood of identifying an ambiguous face as fearful did not differ between the happy sweat and control conditions, there was no direct statistical comparison between the two sweat conditions, which would seem to be a problem.adapted from Fig. 2b (Zhou & Chen, 2009). Nevertheless, there was some evidence that male horror movie sweat was able to bias the women towards viewing an ambiguous face as fearful, and this was not due to the pleasantness (or lack thereof) or intensity of the olfactory stimulus. I'd be curious to see how the "sweat of neutrality" and the "sweat of sexual arousal" [as identified by Zhou & Chen, 2008) in their earlier study] would influence emotion recognition judgments...ReferencesZhou W, Chen D. (2008). Encoding Human Sexual Chemosensory Cues in the Orbitofrontal and Fusiform Cortices. Journal of Neuroscience, 28 (53), 14416-14421.Zhou, W., & Chen, D. (2009). Fear-Related Chemosignals Modulate Recognition of Fear in Ambiguous Facial Expressions. Psychological Science, 20 (2), 177-183. DOI: 10.1111/j.1467-9280.2009.02263.xIntegrating emotional cues from different senses is critical for adaptive behavior. Much of the evidence on cross-modal perception of emotions has come from studies of vision and audition. This research has shown that an emotion signaled by one sense modulates how the same emotion is perceived in another sense, especially when the input to the latter sense is ambiguous. We tested whether olfaction causes similar sensory modulation of emotion perception. In two experiments, the chemosignal of fearful sweat biased women toward interpreting ambiguous expressions as more fearful, but had no effect when the facial emotion was more discernible. Our findings provide direct behavioral evidence that social chemosignals can communicate emotions and demonstrate that fear-related chemosignals modulate humans’ visual emotion perception in an emotion-specific way—an effect that has been hitherto unsuspected.Bonus! See sensory psychologist and olfactory specialist Avery Gilbert's take on these two studies in Basic Instinct: The Smell of Fear and Sex.TAG body spray for sick cats. "This spray is definitely not for me."... Read more »
Zhou, W., & Chen, D. (2009) Fear-Related Chemosignals Modulate Recognition of Fear in Ambiguous Facial Expressions. Psychological Science, 20(2), 177-183. DOI: 10.1111/j.1467-9280.2009.02263.x
"Religion is the Xanax of the people" (Inzlicht et al., 2009).The clever quote above is from the latest paper to garner the _______ Are Neurotic and _______ Are Antisocial style of sensationalistic headline, a study that claims to reveal the Neural Markers of Religious Conviction. I was all prepared to hate the paper, but the authors are not unreasonable in their hypotheses and predictions.But first, a little background. A year and a half ago, Amodio et al. (2007) published an eye-catching article in Nature Neuroscience that reported on supposed "hard-wired" differences in the brains of liberals and conservatives. The typical media feeding frenzy ensued, complete with simplistic headlines (and some interpretive stretching on the part of the authors).As we recounted in The Error of Prognosticating Political View by Brain Wave,1 there were:...overblown quotes:Are We Predisposed to Political Beliefs?. . ."In the past, people thought that…[political leanings were]…all environmentally influenced, a combination of biological dispositions as well as cultural shaping," says David Amodio, an assistant professor of psychology at New York University. However, a new study, led by Amodio, indicates that political bent "is not just a choice people have, but it seems to be linked to fundamental differences in the way people process information."And the baseless assertion of innate differences between the brains of liberals and conservatives:brain neurons of liberals and conservatives fire differently [sic] when confronted with tough choices, suggesting that some political divides may be hard-wired, according a study released Sunday.That study is quite relevant here because Inzlicht and colleagues used the same neural measure as Amodio et al. (2007). Both experiments used EEG recordings, specifically event-related potentials. The ERP brain waves reflect electrophysiological activity recorded remotely from the scalp. While it's great for determining the temporal parameters of neural activity, it's not so great at determining where the activity is located in the brain.The brain wave of interest is the error-related negativity (ERN), recorded at the time that people make mistakes in a task:The ERN is evident as a large negative polarity peak in the event-related brain potential waveform that occurs when people make errors in reaction time tasks. It begins at the moment of the error and reaches a maximum about 100 milliseconds later (see Gehring et al., 1993, PDF). It is largest at fronto-central scalp locations and appears to come from an area of the brain called the anterior cingulate cortex...There is some disagreement about what the ERN wave represents: a direct response to the mismatch between the intended action and the actual one, a more generic response to conflict in general, or an emotional response to f***ing up. And because EEG is recorded from the scalp, one cannot say for certain that the anterior cingulate is the sole origin.What does all this have to do with that old time religion? Inzlicht et al. review the neuropsychology of anxiety and how religion serves to quell the angst:XANAX OF THE PEOPLEOne of religion’s primary functions may be to help people cope with existential uncertainty. In the words of St. Ambrose (ca. 390 AD), ‘‘amid the agitations of the world, the Church remains unmoved; the waves cannot shake her. While around her everything is in a horrible chaos, she offers to all the shipwrecked a tranquil port where they will find safety’’ (quoted in Durant, 1950, p. 79). Religion provides people with a meaning system that helps them navigate through and understand an infinitely complex and uncertain world (Peterson, 1999). It meets the fundamental need to comprehend the deepest problems of existence. Scholars of religion, from James (1902/2002) to Durkheim (1912/1954), have noted that religion imbues life with motivation, purpose, and meaning.What does anxiety have to do with the ERN wave?? It's larger in those with anxiety disorders, as Hajcak et al. (2004) have noted. And the hypothesis of the present paper?How is it that religion can bring about both peace of mind and zealous conviction? We suggest that religious conviction buffers against anxiety by providing relief from the experience of uncertainty and error, and in so doing, strengthening convictions and narrowing attention away from inconsistencies. We hypothesize that this muted response to uncertainty and error is evident neurophysiologically such that religious conviction is associated with reduced activity in the anterior cingulate cortex (ACC), a cortical system involved in a form of attention that serves to regulate both cognitive and emotional processing...Although it's simplistic of them to say the ERN reflects only ACC activity, they did avoid some of the pitfalls of Amodio et al.'s paper by taking into account personality factors that can influence this brain wave (hence, the "neurotic" and "antisocial" title).We measured the amplitude of each participant’s ERN during the Stroop task and correlated these values with participants’ self-reported religious zeal (Study 1) and self-reported belief in God (Study 2). In both studies, we also measured other psychological variables to control for their impact on the hypothesized correlation between religious conviction and ACC activity. We expected greater religious conviction to predict lower ERN amplitudes in both studies, even after controlling for important personality traits and cognitive capacities.And that's what they found.Fig. 1C (Inzlicht et al., 2009). The relation between religious zeal and anterior cingulate cortex activity: event-related potentials (ERPs) at electrode Cz for error-related negativities (ERNs) for people high and low in religious zeal.The Religious Zeal scale was used to assess ardent religious conviction. Items included ‘‘I aspire to live and act according to my religious beliefs,’’ ‘‘My religious beliefs are grounded in objective truth,’’ and ‘‘I would support a war that defended my religious beliefs.’’ Behavioral inhibition, behavioral activation, self-esteem, and the need for cognitive closure were also assessed.However, they repeat some of the drawbacks from Amodio's paper by reporting correlations but only showing a median split (presumably) in the figure (and we don't know if this group difference is significant). We also don't know anything about the reaction times, other than the odd finding that greater religious zealotry was associated with a larger Stroop interference effect (slower for BLUE than for RED) but fewer errors.In Experiment 2 with a different group of subjects, the self-report measures were belief in God, political conservatism à la Amodio, and the Big Five personality inventory. Here, too, they found that greater religious belief correlated with smaller ERN responses to errors (and personality did not account for this).Unexplained loose ends? I see at least two of them. First, the estimated localization of the ERN response within the ACC was centimeters apart in the two groups of subjects. Granted, estimated source localization for ERP is tenuous at best (especially with only 32 electrodes), but these two spots are in different functional regions of the ACC.Fig 1D (top) and Fig 2D (bottom) - illustration of the generator for the ERN (in anterior cingulate cortex), as determined by source localization.More critically, this experiment failed to replicate Amodio's finding: there was absolutely no correlation between self-assessed conservatism and the ERN wave! [as in this figure] I don't have a high need for cognitive closure, but it appears to be a glaring omission that this was not even mentioned in the paper. I'm feeling a very large error-related negativity at the moment. Maybe I need a Xanax. Or a religious experience...Footnote1 For more on the same study, see Liberals Are Neurotic and Conservatives Are Antisocial, as well as David Amodio Responds to his neurocritics.ReferencesAmodio DM, Jost JT, Master SL, Yee CM. (2007). Neurocognitive correlates of liberalism and conservatism. Nature Neurosci. 10:1246-1247.Hajcak G, McDonald N, Simons RF. (2004). Error-related psychophysiology and negative affect. Brain Cogn. 56:189-97.Michael Inzlicht, Ian McGregor, Jacob B. Hirsh, Kyle Nash (2009). Neural Markers of Religious Conviction Psychological Science DOI: 10.1111/j.1467-9280.2009.02305.x... Read more »
Did you know that male "sexual sweat" differs from ordinary sweat? Apparently so, according to a new paper in the Journal of Neuroscience (Zhou & Chen, 2008). Curiously, the article did not cite any references for this, nor did it specify the chemical composition of sexual sweat. Nonetheless, the results of an fMRI experiment suggested that the orbitofrontal cortex and the fusiform region in 20 female participants responded differently when smelling the two substances. How was such a study conducted, you might ask?And here the fun begins...Sweat collection. From 2 d before the experiment until the end of the experiment, 20 heterosexual male donors in a larger study refrained from using deodorant/antiperspirant/scented products, and used scent-free shampoo/conditioner, soap, and lotion provided by the experimenter. They reported to have experience with watching sexually explicit videos, and signed informed consent before participation. Subjects kept a 4" x 4" pad (rayon/polyester for maximum absorbance) in each armpit while they watched 20-min-long video segments intended to produce the emotions of sexual arousal (sexual intercourse between heterosexual couples) and neutrality (educational documentaries), respectively. ... Over the course of the 20 min video segments, donors experienced greater arousal (measured by skin conductance) while watching erotic videos than while watching neutral videos... Three healthy, male nonsmokers (aged 26, 29, and 29 years) were subsequently selected for the current study mainly because of their higher level of the self-reported sexual arousal.How were the female participants selected?We recruited only women for their superior sense of smell and sensitivity to emotional signals. Twenty right-handed females (mean age = 23.4 years) were selected from a group of 42 women on the basis that they reported to have no rhinal disorders or neurological diseases, and that they showed superior olfactory sensitivity to PSP [the putative sex pheromone androstadienone] and PEA [phenyl ethyl alcohol]. They either were in a heterosexual relationship or had been in one within the previous year. They were not on hormone contraceptives, and were tested during the periovulatory phase of their menstrual cycles. ... Subjects were informed that the study was on brain activations to natural compounds. They were blind to the nature of the smells used in the experiment.The scanning was performed while the women were inhaling......the sweat of sexual arousal in comparison with two other social chemosensory compounds (PSP and the sweat of neutrality) and a nonsocial smell [phenyl ethyl alcohol (PEA)].The sweat of neutrality. The sweat of sexual arousal! [plus the two others.] The subjects rated the four inhalants (presented 10 times each) on intensity and pleasantness, as shown below. And the smell of sexual sweat was not particularly pleasant...Figure 1. Mean intensity and pleasantness ratings. There are four types of olfactory stimuli, and SE bars are shown. For intensity, 1 refers to no smell, 2 little smell, 3 moderate smell, 4 quite a bit smell, and 5 strong smell. For pleasantness, 1 refers to very unpleasant, 2 unpleasant, 3 neutral, 4 pleasant, and 5 very pleasant. Sex, Sexual sweat; Neutral, neutral sweat. Sexual sweat and PSP were perceived to be more intense than neutral sweat; PEA was perceived to be more pleasant than sexual sweat and neutral sweat.At the end of the experiment, the participants gave verbal descriptions of the smells. Only one characterized sexual sweat as "sweaty/human." So the women were not [consciously] aware that the odor was obtained from sexually aroused men.The right hypothalamus showed increased activity to sexual sweat relative to alcohol, but so did androstadienone and neutral sweat. The two brain regions that responded more to sexual sweat than to the other odors are illustrated below. The right orbitofrontal cortex is an olfactory region, but the right fusiform gyrus is a high-level visual region. The authors say their fusiform region1 falls in the vicinity of the fusiform face area (FFA) and fusiform body area (FBA). Hmm.Figure 3. a. Coronal view showing an area in the right orbitofrontal cortex (33, 40, –1) activated in the omnibus ANCOVA F test (svc, p less than 0.005). d. Sagittal view showing a region in the right fusiform gyrus (35, –51, –7) activated in the omnibus ANCOVA F test (uncorrected p less than 0.0005, cluster size = 49 mm3).The authors took a giant leap when speculating about visual imagery of faces and bodies:The Talairach coordinates of the fusiform region identified in our experiment fall in the range of the coordinates for FFA and FBA. Such anatomical location likely reflects a recognition of the human quality in the sexual sweat, whose emotional nature may have also contributed to the activation. Considering its functional connectivity to the right hippocampus/ parahippocampal gyrus, the recognition may arise from implicitly associating the sexual sweat with humans based on past experience. The fact that most subjects did not perceive the sexual sweat as human related suggests that the effects we observed occurred at a subconscious level. Implicit face/body visual processing in response to a sexual chemosensory cue? But nothing specific in the hypothalamus or amygdala? That's a hard one to swallow.Footnote1 The FFA and FBA have been dissociated with scanning at high resolution.ReferenceW. Zhou, D. Chen (2008). Encoding Human Sexual Chemosensory Cues in the Orbitofrontal and Fusiform Cortices Journal of Neuroscience, 28 (53), 14416-14421 DOI: 10.1523/JNEUROSCI.3148-08.2008Chemosensory communication of affect and motivation is ubiquitous among animals. In humans, emotional expressions are naturally associated with faces and voices. Whether chemical signals play a role as well has hardly been addressed. Here, we use functional magnetic resonance imaging to show that the right orbitofrontal cortex, right fusiform cortex, and right hypothalamus respond to airborne natural human sexual sweat, indicating that this particular chemosensory compound is encoded holistically in the brain. Our findings provide neural evidence that socioemotional meanings, including the sexual ones, are conveyed in the human sweat.... Read more »
W. Zhou, & D. Chen. (2008) Encoding Human Sexual Chemosensory Cues in the Orbitofrontal and Fusiform Cortices. Journal of Neuroscience, 28(53), 14416-14421. DOI: 10.1523/JNEUROSCI.3148-08.2008
Voodoo doll, by SickboyMost hip researchers in cognitive neuroscience and human brain imaging have already heard about the critical new journal article with the incendiary title: "Voodoo Correlations in Social Neuroscience" (Vul et al., in press - PDF). If you haven't, you can read a comprehensive summary here and a micro version here.Avenging Voodoo SchadenfreudeNature News ran a piece on the debate and the burgeoning backlash from an angry mob of researchers whose methods were derided as fatally flawed. Some of these authors (and perhaps some Nature editors) were miffed that bloggers wrote about the preprint when it was first made available to the public, as if that somehow violates the scientific method:The swift rebuttal was prompted by scientists' alarm at the speed with which the accusations have spread through the community. The provocative title — 'Voodoo correlations in social neuroscience' — and iconoclastic tone have attracted coverage on many blogs, including that of Newsweek. Those attacked say they have not had the chance to argue their case in the normal academic channels."I first heard about this when I got a call from a journalist," comments neuroscientist Tania Singer of the University of Zurich, Switzerland, whose papers on empathy are listed as examples of bad analytical practice. "I was shocked — this is not the way that scientific discourse should take place." Singer says she asked for a discussion with the authors when she received the questionnaire, to clarify the type of information needed, but got no reply.Based on the statements above, it would seem that Dr. Singer and her colleagues (Jabbi, Keysers, and Stephan) are not keeping up with the way that scientific discourse is evolving. [See Mind Hacks on this point as well.] Citing "in press" articles in the normal academic channels is a frequent event; why should bloggers, some of whom are read more widely than the authors' original papers, refrain from such a practice? Is it the "read more widely" part? To their credit, however, they commented in blogs and publicized the link to a preliminary version of their detailed reply.....although calling it "summary information for the press" assumes that "the press" is extremely knowledgeable about neuroimaging methodology and statistical analysis.To learn more about the evolution of scientific discourse, let me briefly introduce you to the world of social media (e.g., FriendFeed, Facebook, and even Twitter). You can join the discussion at FriendFeed's Science 2.0 Room, which is "For people interested in Science 2.0 and Open Science, especially the use of online tools to do science in new ways." Although one needs a Facebook account to view these, Facebook groups include Neuroscience ROCKS (4,006 members), Neuroscience and Brain Studies (3,194 members), and Cognitive Neuroscience Society (2,147 members). Some social neuroscientists are, well, social enough to get it, because Columbia University Social Cognitive Affective Neuroscience Lab has a posse (79 fans, albeit inactive ones). And believe it or not, NIH now has Twitter feeds for press releases and funding announcements. As for individuals who are powerhouse resources on the future of scientific communication, I would recommend reading BoraZ (blog, Twitter), who is organizing the Jan. 16-18 ScienceOnline’09 conference, and Björn Brembs on scientific publishing and misuse of the Impact Factor.All is not puppies and flowers in the world of science social media, however. Proponents rarely acknowledge that many companies and institutions block access to these sites, so at present their usefulness is limited for many in the scientific community. A more obvious issue is that these sites can turn into an enormous time sink.Now back to Nature News and the voodoo backlash. In an ironic twist, one of the 'red listed' papers (Singer et al., 2006), published in Nature, was publicized as a study on Schadenfreude. Here's the Editor's Summary [which was covered by The Neurocritic three years ago]:I feel your painHumans have the capacity to empathize with the pain of others, but we don't empathize in all circumstances. An experiment on human volunteers playing an economic game looked at the conditional nature of our sympathy, and the results show that fairness of social interactions is key to the empathic neural response. Both men and women empathized with the pain of cooperative people. But if people are selfish, empathic responses were absent, at least in men. And it seems that physical harm might even be considered a good outcome — perhaps the first neuroscientific evidence for schadenfreude.Nature and Science have a long history of issuing overblown press releases that extrapolate the findings of a single, quite flawed [if you side with Vul et al.] neuroimaging paper to yield the revelation of deep truths about human social interactions (among other things). The Nature News piece, Brain imaging studies under fire (Abbott, 2009), continues:The article is scheduled for publication in September, alongside one or more replies. But the accused scientists are concerned that the impression now being established through media reports will be hard to shake after the nine-month delay. "We are not worried about our close colleagues, who will understand the arguments. We are worried that the whole enterprise of social neuroscience falls into disrepute," says neuroscientist Chris Frith of University College London, whose Nature paper [Singer et al., 2006] on response to perceived fairness was called into question. So media reports heavily promoted the field, and media reports will unduly tarnish the field.1NewScientist provides a clear instance of this, in what is surely a textbook exemplar of a pot-kettle moment.Doubts raised over brain scan findings14 January by Jim GilesSOME of the hottest results in the nascent field of social neuroscience, in which emotions and behavioural traits are linked to activity in a particular region of the brain, may be inflated and in some cases entirely spurious.But one doesn't have to look very far to find NewScientist headlines like these (I just searched the archives of this blog):Watching the brain 'switch off' self-awarenessDo games prime brain for violence?Starving is like ecstasy use for anorexia sufferersMirror neurons control erection response to pornSource of ‘optimism’ found in the brainSo the NS editorial below comes across as a wee bit hypocritical, even though it eventually acknowledges their own role in promoting "sexy-sounding" brain scan results.Editorial: What were the neuroscientists thinking?14 January 2009IT IS two centuries since the birth of Charles Darwin, but even now his advice can be spot on. The great man attempted a little neuroscience in The Expressions of the Emotions in Man and Animals, published in 1872, in which he discussed the link between facial expressions and the brain. "Our present subject is very obscure," Darwin warned in his book, "and it is always advisable to perceive clearly our ignorance." Modern-day neuroscience might benefit from adopting a similar stance. The field has produced some wonderful science, including endless technicolor images of the brain at work and headline-grabbing papers about the areas that "light up" when registering emotions. Researchers charted those sad spots that winked on in women mourning the end of a relationship, the areas that got fired up when thinking about infidelity, or those that surged in arachnophobes when they thought they were about to see a spider. The subjective subject of feelings seemed at last to be becoming objective. Now it seems that a good chunk of the papers in this field contain exaggerated claims, according to an analysis which suggests that "voodoo correlations" often inflate the link between brain areas and particular behaviours. Some of the resulting headlines appeared in New Scientist, so we have to eat a little humble pie and resolve that next time a sexy-sounding brain scan result appears we will strive to apply a little more scepticism to our coverage.Um, no joke guys.On the other hand, Sharon Begley at Newsweek is one science writer who hasn't been entirely convinced by the colorful brain images. On March 10, 2008, she wrote: Brain-imaging studies have proliferated so mindlessly (no pun intended) that neuroscientists should have to wear a badge pleading, “stop me before I scan again.” I mean, does it really add to the sum total of human knowledge to learn that the brain’s emotion regions become active when people listen to candidates for president? Or that the reward circuitry in the brains of drug addicts become active when they see drug paraphernalia?Therefore, her recent commentary on the brouhaha does not come across as an opinion that was invented yesterday:The 'Voodoo' Science of Brain Imaging If you are a fan of science news, then odds are you are also intrigued by brain imaging, the technique that produces those colorful pictures of brains “lit up” with activity, showing which regions are behind which behaviors, thoughts and emotions. So maybe you remember these recent hits... [gives many examples here] . . . the list goes on and on and on. And now a bombshell has fallen on dozens of such studies: according to a team of well-respected scientists, they amount to little more than voodoo science. The neuroscience blogosphere is crackling with—so far—glee over the upcoming paper, which rips apart an entire field: the use of brain imaging in social neuroscience.....Before concluding, I will state that I am not a complete neuroimaging nihilist. For examples of this view, see Coltheart, 2006 and especially van Orden and Paap, 1997 (as quoted by Coltheart):What has functional neuroimaging told us about the mind so far? Nothing, and it never will: the nature of cognition is such that this technique in principle cannot provide evidence about the nature of cognition.So no, I am not a Jerry Fodor Functionalist. I do believe that learning about human brain function is essential to learing about "the mind," that the latter can be reduced to the former, that fMRI can have something useful to say, and (more broadly, in case any anti-psychiatry types are listening) that psychiatric disorders are indeed caused by faulty brain function. But there's still a lot about fMRI as a technique that we don't really know. The best-practice statistical procedures for analyzing functional images is obviously a contentious issue; there is no consensus at this point. Our knowledge of what the BOLD signal is measuring, exactly, is not very clear either [see the recent announcement in J. Neurosci. that "BOLD Signals Do Not Always Reflect Neural Activity."] The critics among us2 are not trying to trash the entire field of social neuroscience (or neuroimaging in general). Some of us are taking concrete steps to open a dialogue and improve its methodology, while others are trying to rein in runaway interpretations.ADDENDUM: via Pieces of Me, I've just discovered the link to PsyBlog's detailed discussion of the Coltheart paper: Can Cognitive Neuroscience Tell Us Anything About the Mind?Footnote1 It isn't even necessary to quote the appropriate metaphorical expression here.2 By "us" I mean scientists: people who are students and post-docs and colleagues of esteemed investigators like Dr. Frith.ReferencesAbbott A (2009). News: Brain imaging studies under fire. Social neuroscientists criticized for exaggerating links between brain activity and emotions. Nature 457:245.Jabbi M, Keysers C, Singer T, Stephan KE. (in preparation). Rebuttal of "Voodoo Correlations in Social Neuroscience" by Vul et al. – summary information for the press. PDFSinger T, Seymour B, O'doherty JP, Stephan KE, Dolan RJ, Frith CD. (2006) Empathic neural responses are modulated by the perceived fairness of others. Nature 439:466-9.Vul E, Harris C, Winkielman P, Pashler H (2009). Voodoo Correlations in Social Neuroscience. Perspectives on Psychological Science, in press. PDF... Read more »
The end of 2008 brought us the tabloid headline, Scan Scandal Hits Social Neuroscience. As initially reported by Mind Hacks, a new "bombshell of a paper" (Vul et al., 2009) questioned the implausibly high correlations observed in some fMRI studies in Social Neuroscience. A new look at the analytic methods revealed that over half of the sampled papers used faulty techniques to obtain their results.Edward Vul, the first author, deserves a tremendous amount of credit (and a round of applause) for writing and publishing such a critical paper under his own name [unlike all those cowardly pseudonymous bloggers who shall go unnamed here]. He's a graduate student in Nancy Kanwisher's Lab at MIT. Dr. Kanwisher1 is best known for her work on the fusiform face area.Credit (of course) is also due to the other authors of the paper (Christine Harris, Piotr Winkielman, and Harold Pashler), who are at the University of California, San Diego. So without further ado, let us begin.A Puzzle: Remarkably High Correlations in Social NeuroscienceVul et al. start with the observation that the new field of Social Neuroscience (or Social Cognitive Neuroscience) has garnered a great deal of attention and funding in its brief existence. Many high-profile neuroimaging articles have been published in Science, Nature, and Neuron, and have received widespread coverage in the popular press. However, all may not be rosy in paradise:2Eisenberger, Lieberman, and Williams (2003), writing in Science, described a game they created to expose individuals to social rejection in the laboratory. The authors measured the brain activity in 13 individuals at the same time as the actual rejection took place, and later obtained a self-report measure of how much distress the subject had experienced. Distress was correlated at r=.88 with activity in the anterior cingulate cortex (ACC).In another Science paper, Singer et al. (2004) found that the magnitude of differential activation within the ACC and left insula induced by an empathy-related manipulation was correlated between .52 and .72 with two scales of emotional empathy (the Empathic Concern Scale of Davis, and the Balanced Emotional Empathy Scale of Mehrabian).Why is a correlation of r=.88 with 13 subjects considered "remarkably high"? For starters, it exceeds the reliability of the hemodynamic and behavioral (social, emotional, personality) measurements:The problem is this: It is a statistical fact... that the strength of the correlation observed between measures A and B reflects not only the strength of the relationship between the traits underlying A and B), but also the reliability of the measures of A and B.Evidence from the existing literature suggests the test-retest reliability of personality rating scales to be .7-.8 at best, and a reliability no higher than .7 for the BOLD (Blood-Oxygen-Level Dependent) signal. If each of these measures was [impossibly] perfect, then the highest possible correlation would be sqrt(.8 * .7), or .74.This observation prompted the authors to conduct a meta-analysis of the literature. They identified 54 papers that met their criteria for fMRI studies reporting correlations between the BOLD response in a particular brain region and some social/emotional/personality measure. In most cases, the Methods sections did not provide enough detail about the statistical procedures used to obtain these correlations. Therefore, a questionnaire was devised and sent to the corresponding authors of all 54 papers:APPENDIX 1: fMRI Survey Question TextWould you please be so kind as to answer a few very quick questions about the analysis that produced, i.e., the correlations on page XX. We expect this will just take you a minute or two at most.To make this as quick as possible, we have framed these as multiple choice questions and listed the more common analysis procedures as options, but if you did something different, we'd be obliged if you would describe what you actually did.The data plotted reflect the percent signal change or difference in parameter estimates (according to some contrast) of...1. ...the average of a number of voxels.2. ...one peak voxel that was most significant according to some functional measure.3. ...something else?etc.....Thank you very much for giving us this information so that we can describe your study accurately in our review.They received 51 replies. Did these authors suspect the final product could put some of their publications in such a negative light?SpongeBob: What if Squidward’s right? What if the award is a phony? Does this mean my whole body of work is meaningless?After providing a nice overview of fMRI analysis procedures (beginning on page 6 of the preprint), Vul et al. present the results of the survey, and then explain the problems associated with the use of non-independent analysis methods....23 [papers] reported a correlation between behavior and one peak voxel; 29 reported the mean of a number of voxels. ... Of the 45 studies that used functional constraints to choose voxels (either for averaging, or for finding the ‘peak’ voxel), 10 said they used functional measures defined within a given subject, 28 used the across-subject correlation to find voxels, and 7 did something else. All of the studies using functional constraints used the same data to select voxels, and then to measure the correlation. Notably, 54% of the surveyed studies selected voxels based on a correlation with the behavioral individual-differences measure, and then used those same data to compute a correlation within that subset of voxels.Therefore, for these 28 papers, voxels were selected because they correlated highly with the behavioral measure of interest. Using simulations, Vul et al. demonstrate that this glaring "non-independence error" can produce significant correlations out of noise!This analysis distorts the results by selecting noise exhibiting the effect being searched for, and any measures obtained from such a non-independent analysis are biased and untrustworthy (for a formal discussion see Vul & Kanwisher, in press, PDF).And the problem is magnified in correlations that used activity in one peak voxel (out of a grand total of between 40,000 and 500,000 voxels in the entire brain) instead of a cluster of voxels that passed a statistical threshold. Papers that used non-independent analyses were much more likely to report implausibly high correlations, as illustrated in the figure below.Figure 5 (Vul et al., 2009). The histogram of the correlations values from the studies we surveyed, color-coded by whether or not the article used non-independent analyses. Correlations coded in green correspond to those that were achieved with independent analyses, avoiding the bias described in this paper. However, those in red correspond to the 54% of articles surveyed that reported conducting non-independent analyses – these correlation values are certain to be inflated. Entries in orange arise from papers whose authors chose not to respond to our survey.Not so coincidentally, some of these same papers have been flagged (or flogged) in this very blog. The Neurocritic's very first post 2.94 yrs ago, Men are Torturers, Women are Nurturers..., complained about the overblown conclusions and misleading press coverage of a particular paper (Singer et al., 2006), as well as its methodology:And don't get me started on their methodology -- a priori regions of interest (ROIs) for pain-related empathy in fronto-insular cortex and anterior cingulate cortex (like the relationship between those brain regions and "pain-related empathy" are well-established!) -- and on their pink-and-blue color-coded tables!Not necessarily the most sophisticated deconstruction of analytic techniques, but it was the first...and it did question how the regions of interest were selected. And of course how the data were interpreted and presented in the press.SUMMARY from The Neurocritic : Ummm, it's nice they can generalize from 16 male undergrads to the evolution of sex differences that are universally valid in all societies.As you can tell, this one really bothers me...And what are the conclusions of Vul et al.?To sum up, then, we are led to conclude that a disturbingly large, and quite prominent, segment of social neuroscience research is using seriously defective research methods and producing a profusion of numbers that should not be believed.Finally, they call upon the authors to re-analyze their data and correct the scientific record.Footnotes1 Kanwisher was elected to the prestigious National Academy of Sciences in 2005.2 The authors note that the problems are probably not unique to neuroimaging papers in this particular subfield, however.ReferencesEisenberger NI, Lieberman MD, Williams KD. (2003). Does rejection hurt? An FMRI study of social exclusion. Science 302:290-2.Singer T, Seymour B, O'Doherty J, Kaube H, Dolan RJ, Frith CD. (2004). Empathy for pain involves the affective but not sensory components of pain. Science 303:1157-62.Singer T, Seymour B, O'doherty JP, Stephan KE, Dolan RJ, Frith CD. (2006) Empathic neural responses are modulated by the perceived fairness of others. Nature 439:466-9.Edward Vul, Christine Harris, Piotr Winkielman, & Harold Pashler (2009). Voodoo Correlations in Social Neuroscience. Perspectives on Psychological Science, in press. PDFVul E, Kanwisher N. (in press). Begging the question: The non-independence error in fMRI data analysis. To appear in Hanson, S. & Bunzl, M (Eds.), Foundations and Philosophy for Neuroimaging. PDF... Read more »
OR: Is Perceptual Decision Making in Primate LIP Equivalent to Financial Decision Making Under Risk?In the universally familiar game show Deal or No Deal, contestants choose from among 26 briefcases held by 26 models. Each of these briefcases contains a different amount of money ranging from $0.01 to $1,000,000. The contestant begins by choosing one briefcase, then starts selecting other cases to open, hoping to reveal small cash amounts because this will improve the odds of winning the $1 million. After a predetermined number of cases are opened, 'the Banker' tries to tempt the player to exchange her case for an amount of instant cash. The player must either stick with her original briefcase choice ('No Deal'), or make a 'Deal' with the Banker to accept his cash offer in exchange for whatever dollar amount is in the chosen case.The show is a terrific example of financial decision making under risk. Nobel prize recipient Daniel Kahneman and his colleague Amos Tversky developed the idea of prospect theory to explain how people decide between alternatives that involve risk, when the outcome is uncertain but the probabilities are known (or estimated). Their highly influential paper (Kahneman & Tversky, 1979) framed these ideas, which provided an alternative to the expected utility hypothesis:What does any of this have to do with dots??The University of Rochester issued an egregiously erroneous press release to accompany the publication of a new paper in Neuron (Beck et al., 2008):Our Unconscious Brain Makes the Best Decisions PossibleNew Research Shows the Human Brain Computes Extremely Well—Given What it KnowsResearchers at the University of Rochester have shown that the human brain—once thought to be a seriously flawed decision maker—is actually hard-wired to allow us to make the best decisions possible with the information we are given.Let's see, the study was done in monkeys (not humans), and the results said absolutely nothing about proving the brain is "hard-wired" to make the best decisions possible. The paper used computational methods to analyze the spike trains of neurons in the lateral intraparietal (LIP) area of monkeys who were trained to make motion discriminations. The original data were taken from the paper of Anne Churchland et al. (2008). One of the experimental tasks is illustrated below.Figure 1A (Beck et al., 2008). Binary decision making. The subject must decide whether the dots are moving to the right or to the left. Only a fraction of the dots are moving to the right or the left coherently (black arrows). The other dots move in random directions. The animal indicates its response by moving its eyes in the perceived direction (green arrow).Another variant of the task involved four choices instead of two (Churchland et al., 2008). In the Neuron paper, Beck et al. described a neural network model of decision making in these tasks. Although the motion direction task has been extensively studied in both animals and humans, the reported model is clearly based on recordings of LIP neurons in rhesus monkeys.Back to paragraph #2 of the press release:Neuroscientists Daniel Kahneman and Amos Tversky received a 2002 Nobel Prize for their 1979 research that argued humans rarely make rational decisions. Since then, this has become conventional wisdom among cognition researchers.Kahneman and Tversky are/were (respectively) psychologists, not neuroscientists, and Tversky did not receive the Nobel prize. Perceptual discrimination of motion direction is not the same thing as financial decision making under risk, with its cognitive and affective elements. Although the monkeys were rewarded for correct decisions, reward functions were not a part of the network model. The authors summarized the significance of their work as follows:First, we show that for Poisson-like distributions, optimal evidence accumulation can be performed through simple integration of neural activities, while optimal response selection can be implemented through attractor dynamics. Second, we show (again for Poisson-like distributions of neural activity) that neurons encode the posterior probability distribution over the variables of interest at all times. This latter contribution has far-reaching implications, since it suggests that neurons implicated in simple perceptual decisions represent quantities that are directly relevant to inference, confidence, and belief.However, they didn't directly extrapolate their results to behavioral economics, and they didn't cite Kahneman and Tversky. Neverthess, the press release by the Senior Science Press Officer continues:Contrary to Kahnneman and Tversky's research, Alex Pouget, associate professor of brain and cognitive sciences at the University of Rochester, has shown that people do indeed make optimal decisions—but only when their unconscious brain makes the choice.At the risk of sounding pedantic, people did not make the decisions (monkeys did), and there was nary a mention of conscious vs. unconscious processing in the paper."A lot of the early work in this field was on conscious decision making, but most of the decisions you make aren't based on conscious reasoning," says Pouget. "You don't consciously decide to stop at a red light or steer around an obstacle in the road. Once we started looking at the decisions our brains make without our knowledge, we found that they almost always reach the right decision, given the information they had to work with." Pouget says that Kahneman's approach was to tell a subject that there was a certain percent chance that one of two choices in a test was "right." This meant a person had to consciously compute the percentages to get a right answer—something few people could do accurately.. . ."We've been developing and strengthening this hypothesis for years—how the brain represents probability distributions," says Pouget. "We knew the results of this kind of test fit perfectly with our ideas, but we had to devise a way to see the neurons in action. We wanted to see if, in fact, humans are really good decision makers after all, just not quite so good at doing it consciously. Kahneman explicitly told his subjects what the chances were, but we let people's unconscious mind work it out. It's weird, but people rarely make optimal decisions when they are told the percentages up front."I don't know if there would be any differences in the results if the monkeys were told the percentages up front... but you can watch Professor Kahneman discuss Decision Making and Rationality in Deal or No Deal Decisions, now showing on Channel N.ReferencesJ BECK, W MA, R KIANI, T HANKS, A CHURCHLAND, J ROITMAN, M SHADLEN, P LATHAM, A POUGET (2008). Probabilistic Population Codes for Bayesian Decision Making Neuron, 60 (6), 1142-1152 DOI: 10.1016/j.neuron.2008.09.021Churchland AK, Kiani R, Shadlen MN. (2008). Decision-making with multiple alternatives. Nat Neurosci. 11:693-702.Kahneman D, Tversky A. (1979). Prospect theory: An analysis of decision under risk. Econometrica 47: 263-291.... Read more »
J BECK, W MA, R KIANI, T HANKS, A CHURCHLAND, J ROITMAN, M SHADLEN, P LATHAM, & A POUGET. (2008) Probabilistic Population Codes for Bayesian Decision Making. Neuron, 60(6), 1142-1152. DOI: 10.1016/j.neuron.2008.09.021
OR: The Glasgow Coma Scale-Revised: The Texting Sign.Watch Killing in the Name, live at the Reading Festival 2008.Rage Against the Machine SyncopeFirst we had dangerous sandwiches. Now we have dangerous concerts, as described in an article in the special Christmas edition of BMJ by Mike Sinclair and colleagues (Sinclair et al., 2008). They examined the utility of texting ability as a sign of return to consciousness after fainting or panic attack at large outdoor music festivals in the UK:Three years ago we noticed that most of the patients with faint [syncope] or panic attack were teenagers and as soon as they could they used their mobile phones to send an SMS (short message service) text message to their friends... The ability to text, whether or not it actually makes sense, requires a Glasgow coma scale score of 15 (fully conscious), an adequately functioning "executive system" in the frontal lobes, and a high degree of manual dexterity and psychomotor coordination. It also shows a degree of common sense not always evident in teenagers. Two years ago we decided to use this texting sign as an indication that patients had recovered from their faint or panic attack and were orientated and coordinated enough to be discharged back to the festival. At times of massive influx to the medical tent, when up to two patients a minute are triaged, this system seems to work well.The sets by Bloc Party and Rage Against the Machine were particularly busy times. The Festival Medical Services pit crew was able to treat142 patients in less than 60 minutes during the performance by Bloc Party and 130 patients over 90 minutes during the performance by Rage Against the Machine. The texting sign needs further investigation to determine whether it is a valid criterion for recovery after faint or panic attack at festivals as well as in busy accident and emergency departments.And now you do what they told ya (11 times)...For another music-related article from the same issue of BMJ, see Between a rock and a hard bass in Mind Hacks.ReferenceM. Sinclair, D. W Pigott, K. N Carpenter (2008). Texting shows recovery after faint. BMJ, 337. DOI: 10.1136/bmj.a2723.... Read more »
PLoS ONE @ TwoOriginally posted on Thursday, January 10, 2008. On the corner of main streetJust tryin' to keep it in lineYou say you wanna move on andinstead of falling behindCan you read my mind?Can you read my mind?Read My Mind ------The KillersEarlier this year, a study in PLoS One (Shinkareva et al., 2008) received some wildly overblown coverage in the media:Scientists can read your mind... sort ofTHOUGHTS are successfully being read for the first time by scientists using nothing but a modified MRI scanner and a special computer program.Very briefly, subjects viewed pictures of 10 different objects: 5 tools (drill, hammer, screwdriver, pliers, saw) and 5 dwellings (apartment, castle, house, hut, and igloo). Previous work had shown that these two object categories activate some unique brain regions (e.g., ventral premotor cortex and parahippocampal gyrus, respectively). Machine learning methods were used to classify the patterns of activity obtained while subjects viewed each of these pictures, with a goal of identifying individuals objects (not just the categories) by the distinctive neural activity associated with each.But is it humans who are doing the mind-reading, or is it...is it...THE COMPUTERS!! Ahh, they're taking over!CMU computers seek where thoughts originateBy Allison M. HeinrichsTRIBUNE-REVIEWFriday, January 4, 2008Computers are reading minds at Carnegie Mellon University.In a small two-year study, computer scientists and cognitive neuroscientists teamed up to teach computers to recognize patterns in brain activity and identify objects that people are looking at.Scientists call it the first step toward identifying where people's thoughts originate, while ethicists see it as a sign of the need for new public policy.Colossus - The Forbin Project takes place in the 50s during the height of the cold war. Dr. Charles Forbin, a genius scientist who has lost trust in humanity’s ability to logically address emotional issues, has developed a very special computer to perform the Strategic Air Command and Control functions for the military. This computer, code named Colossus, is developed based on incredible advances in Artificial Intelligence, and has a logical process for determining when to launch the ICBMs. With much fanfare, the President of the US “turns on” Colossus to take over responsibility for the US nuclear armament. [from Cyberpunk Review]"I want a complete mapping of brain states and thoughts," Dr. Just said. "We're taking tiny baby steps, but anything we can think about is represented in the brain." In coming years, researchers will be able to develop a fairly complex mapping of brain states and thoughts, he said. "It's a little science fiction-y, and I don't think we'll do it in one year, but five to 10 is plausible," he said.Unfortunately, shortly after being turned on, Colossus learns the presence of another AI command and control system. It turns out that the Soviet Union, independently has developed their own system call the Guardian. Both computers “insist” that they be linked to ensure no attacks will take place... Wikipedia defines machine learning as a broad subfield of artificial intelligence, concerned with the design and development of algorithms and techniques that allow computers to "learn". ... Inductive machine learning methods extract rules and patterns out of massive data sets. The major focus of machine learning research is to extract information from data automatically, by computational and statistical methods. Hence, machine learning is closely related not only to data mining and statistics, but also theoretical computer science.Things begin to go downhill when Professor Forbin realizes that the rate of learning for the machines is increasing at an exponential rate – he recommends detaching the connection between the two computers. When they attempt to do this, both computers threaten an immediate launch of nuclear weapons. Quickly, the government’s realize their situation – the machines are now in power. Worse, they proceed to take complete control of human society.In the PLoS One article, Shinkareva et al. (2008) describe this approach to analyzing functional imaging data as involvingidentification of a multivariate pattern of voxels and their characteristic activation levels that collectively identify the neural response to a stimulus. These machine learning methods have the potential to be particularly useful in uncovering how semantic information about objects is represented in the cerebral cortex because they can determine the topographic distribution of the activation and distinguish the content of the information in various parts of the cortex. In the study reported below, the neural patterns associated with individual objects as well as with object categories were identified using a machine learning algorithm applied to activation distributed throughout the cortex. This study also investigated the degree to which objects and categories are similarly represented neurally across different people.And wouldn't you know it, people [Carnegie Mellon students] are people.CMU finds human brains similarly organizedCarnegie Mellon University has taken an important step in mapping thought patterns in the human brain, and the research has produced an amazing insight: Human brains are similarly organized. Based on how one person thinks about a hammer, a computer can identify when another person also is thinking about a hammer. It also can differentiate between items in the same category of tools, be it a hammer or screwdriver.Results revealed the typical-ish distributed activity patterns underlying object representations, and high classification rank accuracies for object exemplars:Reliable (p less than 0.001) accuracies for the classification of object exemplars within participants were reached for eleven out of twelve participants, and reliable (p less than 0.001) accuracies for the classification of object exemplars when training on the union of data from eleven participants were reached for eight out of twelve participants.From Table 1 (Shinkareva et al., 2008). Anatomical regions (out of 71) that singly produced reliable average classification accuracies across the twelve participants for category identification.L Precentral gyrusL Superior frontal gyrusL Inferior frontal gyrus, triangular partL Insula, rolandic operculumL/R Calcarine fissureL/R Cuneus, superior occipital, middle occipital gyriL/R Inferior occipital, lingual gyriL/R Fusiform gyrusL Postcentral gyrusL/R Superior parietal gyrus, precuneus, paracentral lobuleL/R Inferior parietal, supramarginal, angular gyriL/R Intraparietal sulcusL/R Posterior superior temporal, posterior middle temporal gyriL/R Posterior inferior temporal gyrusL/R Cerebellum"This part of the study establishes, as never before, that there is a commonality in how different people's brains represent the same object," said Mitchell, head of the Machine Learning Department in Carnegie Mellon's School of Computer Science and a pioneer in applying machine learning methods to the study of brain activity. "There has always been a philosophical conundrum as to whether one person's perception of the color blue is the same as another person's. Now we see that there is a great deal of commonality across different people's brain activity corresponding to familiar tools and dwellings." "This first step using computer algorithms to identify thoughts of individual objects from brain activity can open new scientific paths, and eventually roads and highways," added Svetlana Shinkareva, an assistant professor of psychology at the University of South Carolina who is the study's lead author. "We hope to progress to identifying the thoughts associated not just with pictures, but also with words, and eventually sentences."In contrast to this last statement are the results from a new paper (Sanai et al., 2008) showing that language representation in the brain is highly variable across individuals:Background: Language sites in the cortex of the brain vary among patients. Language mapping while the patient is awake is an intraoperative technique designed to minimize language deficits associated with brain-tumor resection. ...Results: ...Cortical maps generated with intraoperative language data ...showed surprising variability in language localization within the dominant [left] hemisphere.During surgery to remove gliomas, the patients in the mapping study performed three different speech/language tasks (including object naming) while various regions of cortex were stimulated to test for language deficits. Guess the neurosurgeons couldn't read their minds...ReferencesSanai N, Mirzadeh Z, Berger MS. (2008). Functional outcome after language mapping for glioma resection. N Engl J Med. 358:18-27.Svetlana V. Shinkareva, Robert A. Mason, Vicente L. Malave, Wei Wang, Tom M. Mitchell, Marcel Adam Just (2008). Using fMRI Brain Activation to Identify Cognitive States Associated with Perception of Tools and Dwellings. PLoS ONE, 3 (1) DOI: 10.1371/journal.pone.0001394Previous studies have succeeded in identifying the cognitive state corresponding to the perception of a set of depicted categories, such as tools, by analyzing the accompanying pattern of brain activity, measured with fMRI. The current research focused on identifying the cognitive state associated with a 4s viewing of an individual line drawing (1 of 10 familiar objects, 5 tools and 5 dwellings, such as a hammer or a castle). Here we demonstrate the ability to reliably (1) identify which of the 10 drawings a participant was viewing, based on that participant's characteristic whole-brain neural activation patterns, excluding visual areas; (2) identify the category of the object with even higher accuracy, based on that participant's activation; and (3) identify, for the first time, both individual objects and the category of the object the participant was viewing, based only on other participants' activation patterns. The voxels important for category identification were located similarly across participants, and distributed throughout the cortex, focused in ventral temporal perceptual areas but also including more frontal association areas (and somewhat left-lateralized). These findings indicate the presence of stable, distributed, communal, and identifiable neural states corresponding to object concepts.... Read more »
Svetlana V. Shinkareva, Robert A. Mason, Vicente L. Malave, Wei Wang, Tom M. Mitchell, & Marcel Adam Just. (2008) Using fMRI Brain Activation to Identify Cognitive States Associated with Perception of Tools and Dwellings. PLoS ONE, 3(1). DOI: 10.1371/journal.pone.0001394
RT @Dostoyevsky Realists do not fear the results of their study."Good God!" he cried, "can it be, can it be, that I shall really take an axe, that I shall strike her on the head, split her skull open... that I shall tread in the sticky warm blood, blood... with the axe... Good God, can it be?"- Fyodor Dostoevsky, Crime and Punishment, Ch. 5A new fMRI paper in Neuron (Buckholtz et al., 2008) claims to have discovered the neural correlates of evaluating another person's crime and deciding on the appropriate sentence, in emulation of judges and juries meting out third-party punishment (Fehr & Fischbacher, 2004).On the other hand, the rotating "freak show" guests on the Jerry Springer Show mete out second-party punishment,1 which is generally harsher (in midget fights and certain economic games, at least).Here’s the great new insight of the paper, according to the Preview by Johannes Haushofer and Ernst Fehr:Thus, the study of Buckholtz makes a valuable contribution in that it illustrates that third-person judgment situations, such as those used in their study, may rely on similar neural mechanisms as two-person economic and social exchanges. While it is difficult to draw reverse inferences about mental states based on brain activation (Poldrack, 2006),2 one might speculate, based on this new study, that the mental processes motivating judicial verdicts involve the suppression of prepotent emotional reactions in favor of impartial and objective verdicts.[NOTE: aren’t you just marveling at this grand new insight from fMRI? Like we didn’t already know that judges and jurors must put aside their emotionally-driven desire for revenge when coming to an impartial verdict.]Thus, this new result might, if confirmed by future studies, elucidate the neural source of judicial impartiality.All right, let's go back to the beginning. Or to the Methods, at least. One of the experimental tasks was to determine whether the perpetrator of a given hypothetical crime was responsible for his actions. There were two versions of the same basic crime scenarios with the details of Responsibility versus Diminished Responsibility counterbalanced across the two sets (e.g., compare #3 and #32 below). Half of the participants read Set 1, the other half read Set 2. Some of the infractions were minor (#7, #22), but some were crimes of the most heinous sort, whether intentional (#3) or unintentional (#27, #32). Thus, the severity of the crimes was matched across the experimental conditions as well. Below are some examples of the stimuli, taken from the Supplementary Materials. Responsibility Scenarios 3) John develops a plan to kill his 60-year-old invalid mother for the inheritance. He drags her to her bed, puts her in, and lights her oxygen mask with a cigarette, hoping to make it look like an accident. His mother screams as her clothes catch fire and she burns to death. 7) John is parking his car in the parking lot of a local football stadium, where he plans to watch a game. In the car next to his, he sees a hat with his team logo in the back seat. Seeing that the door is unlocked, John opens the door, and takes the hat. Diminished Responsibility Scenarios 22) John visits a local bookstore, carrying a large shopping bag with goods from another store. While the store clerk is preoccupied with inventory, another customer, hoping to use John unwittingly in a theft, sneaks a book into John’s shopping bag. Without realizing what has happened, John walks out without paying for the book. 27) A brain tumor is causing increasingly erratic, violent, and callous behavior in John. Soon, he develops an uncontrollable urge to kill. John abducts a boy, puts a broomstick in the boy’s r-----, and lashes him with a whip until he dies. When the tumor is later found and removed, John’s behavior returns to normal. 32) Unbeknownst to John and his doctors, his new prescription interacts with his other medications to induce severe acute psychoses. During that interaction, John returns home to his 60-year old invalid mother, who he has always adored. John lights her oxygen mask with a cigarette, and watches as his mother catches fire, screams, and burns to death. No Crime Scenarios [control condition] 47) The manual to John’s new car states: “The oil must be changed no less frequently than every 4,000 miles.” John reads the manual and is aware of what it says. However, John drives the car for 4,023 miles before taking it to a service station for the car’s first oil change. [gasp!] 48) John and his best friend have played golf together for more than ten years. They used to be evenly matched, but recently John’s friend has consistently outplayed him. Growing frustrated, John responded by taking private golf lessons from the local pro. The next time John played against his friend, he soundly beat him.That was extremely unpleasant and harsh at times, wasn't it? Over the course of the experiment, participants read 50 scenarios (20 Responsibility, 20 Diminished Responsibility, 10 No Crime) three times each: once in the scanner and twice after scanning. The procedures were as follows:Participants rated each scenario on a scale from 0–9, according to how much punishment they thought John deserved, with “0” indicating no punishment and “9” indicating extreme punishment. Punishment was defined for participants as “deserved penalty.”. . .Following the scanning session, participants rated the same scenarios along scales of emotional arousal and valence. They first rated each of the 50 scenarios (presented in random order on a computer screen outside the scanner) on the basis of how emotionally aroused they felt following its presentation (0 = calm, 9 = extremely excited). They then rated each of the scenarios, presented again in random order, on the basis of how positive or negative they felt following its presentation (0 = extremely positive, 9 = extremely negative).The results from these rating tasks are shown below, and it's not surprising that the subjects recommended more severe punishments for the perpetrator in the Responsibility scenarios than in the Diminished Responsibility scenarios.Figure 1 (Buckholtz et al., 2008). Punishment and Arousal Ratings for Each Scenario Type. While punishment and arousal scores were similar in the Responsibility condition, punishment scores were significantly lower than arousal scores in the Diminished-Responsibility condition. Error bars = SEM.As for the neuroimaging results, the authors compared the hemodynamic response in the Responsibility versus the Diminished Responsibility conditions to see what brain areas might be differentially activated. Greater activity in the right dorsolateral prefrontal cortex (rDLPFC) was emphasized (Fig 2). Responses in bilateral anterior intraparietal sulcus were similar, but relegated to the Supplementary Materials.Figure 2 (Buckholtz et al., 2008). Relationship between Responsibility Assessment and rDLPFC Activity. (A) SPM displaying the rDLPFC VOI, based on the contrast of BOLD activity between the Responsibility and Diminished-Responsibility conditions. (B) BOLD activity time courses. BOLD peak amplitude was significantly greater in the Responsibility condition compared with both the Diminished-Responsibility and No-Crime conditions.So now we get to the interpretation that rDLPFC is suppressing emotional reactions in areas such as the amygdala, medial PFC, and posterior cingulate cortex (which were sensitive to the magnitude of punishment) in order to assign a diminished level of criminal responsibility. The problem with that reverse inference is illustrated below.This figure was generated from entering the x, y, z Talairach coordinates from the rDLPFC focus shown above (39, 37, 22)3 into the Sleuth program (available at brainmap.org), which searched the available database of papers for matches. The resulting list of coordinates and experiments was then imported into the GingerALE program, which performed a meta-analysis via the activation likelihood estimation (ALE) method (see this PDF). The figure illustrates that the exact same region of rDLPFC was activated during tasks that assessed attention; execution, inhibition, and observation of actions; various aspects of language and perception; and especially working memory.The authors appear to acknowledge the caveat thatthe brain regions identified in our study are not specifically devoted to legal decision-making. Rather, a more parsimonious explanation is that third-party punishment decisions draw on elementary and domain-general computations supported by the rDLPFC.They also acknowledged the confound of arousal and crime severity. Nonetheless, they concluded by waving their arms around and blabbing about the evolution of the legal system:...on the basis of the convergence between neural circuitry mediating second-party norm enforcement and impartial third-party punishment, we conjecture that our modern legal system may have evolved by building on preexisting cognitive mechanisms that support fairness-related behaviors in dyadic interactions. Though speculative and subject to experimental confirmation, this hypothesis is nevertheless consistent with the relatively recent development of state-administered law enforcement institutions, compared to the much longer existence of human cooperation.What are we to conclude from this? Since it's very late now, I'll let Jerry and Fyodor have the last words.“We can't just have mainstream behavior on television in a free society, we have to make sure we see the whole panorama of human behavior.”- Jerry Springer“Actions are sometimes performed in a masterly and most cunning way, while the direction of the actions is deranged and dependent on various morbid impressions-it's like a dream.”- Fyodor Dostoevsky, Crime and Punishment, Ch. 17But when all is said and done, why don't we let Jerry Fodor have the last word?“It’s a thin line between clarity and pomposity.” — Psychosemantics: The Problem of Meaning in the Philosophy of Mind, p. 17.Footnotes1 But as Wikipedia notes, "there has been continuous debate over the actual authenticity of the fighting."2 "...we won’t let that stop us from rampant speculation" [to paraphrase Haushofer and Fehr]. I feel like a broken record here, but reverse inference is a logical fallacy - one cannot directly infer the participants' cognitive or emotional state from the observed pattern of brain activity. Everyone should know better by now, and there should be a moratorium on such sloppy thinking. Or rather, such sloppy writing and publishing. The high-profile journals are the worst offenders, and they end up promoting the use of totally misleading headlines like this one:Justice may be hard-wired into the human brainCall it the justice instinct. When judging the guilt or innocence of alleged criminals, our brains seem to respond as if we were personally wronged, say researchers.The "justice instinct"?? Spare me. The experiment said absolutely nothing about evolution, genetics, or "hard-wiring."3 According to pages 932 and 938. However, page 936 and Table S1 say the coordinates are slightly different: 39, 38, 18.ReferencesJ BUCKHOLTZ, C ASPLUND, P DUX, D ZALD, J GORE, O JONES, R MAROIS (2008). The Neural Correlates of Third-Party Punishment. Neuron, 60 (5), 930-940 DOI: 10.1016/j.neuron.2008.10.016.Fehr E, Fischbacher U. (2004). Third-party punishment and social norms. Evolution and Human Behavior 25:63–87.Haushofer J, Fehr E (2008). You Shouldn’t Have: Your Brain on Others’ Crimes. Neuron 60:738-740.Ax Murderer FAIL... Read more »
OR: Why is the RSNA Makin' Stuff Up?First, we had the latest new scourge among teenage girls, as featured in yesterday's post:Self-Embedding Disorder appears to be a newly-coined term described in a press release issued by the Radiological Society of North America (RSNA):Radiologists Diagnose and Treat Self-Embedding Disorder in TeensCHICAGO — Minimally invasive, image-guided treatment is a safe and precise method for removal of self-inflicted foreign objects from the body, according to the first report on "self-embedding disorder," or self-injury and self-inflicted foreign body insertion in adolescents. The findings will be presented today at the annual meeting of the Radiological Society of North America (RSNA). A quick PubMed search shows that although "self-embedding disorder" resulted in zero hits, "self-harm, foreign" yielded 17 references, with the most relevant being:Wraight WM, Belcher HJ, Critchley HD. (2008). Deliberate self-harm by insertion of foreign bodies into the forearm. J Plast Reconstr Aesthet Surg. 61:700-3. Epub 2007 Jun 20.Deliberate self-harm is common. It is usually by drug overdose or ingestion of other noxious substances, but self-harm by cutting or burning often comes to the attention of plastic surgeons. We report three variant cases involving insertion of paperclips, a ballpoint pen cartridge and sewing needles into the forearm. We discuss the management considerations of each case and emphasise the importance of actively addressing the underlying psychiatric problems for all instances of deliberate self-harm.OK, the case reports were from three adult women (not teen girls), but it's not exactly a new phenomenon. It's a form of self-injury, which has been widely reported in the literature (more broadly), and is well-known to clinicians.Figure 2 (Wraight et al., 2008). Case A, dorso-palmar and lateral radiographs of left forearm.Case A:A 42-year-old woman with a history of depression, personality disorder and deliberate self-harm by drug overdose and cutting was referred for non-healing wounds of her left, non-dominant forearm (Fig. 1). Over the preceding five years the self-harm included subcutaneous insertion of straightened-out paperclips. Consequently, abscesses had formed intermittently and were managed by incision and drainage with removal of the causative paperclip. Nevertheless, numerous paperclips remained embedded in subcutaneous tissue (Fig. 2), engendering ferrous staining of the skin and overgranulating chronic ulcers. There was no functional deficit in the hand or forearm at the time of assessment.Wraight and his colleagues are from Plastic Surgery and Psychiatry Departments (not Radiology Departments), so the emphasis of their short Case Report was different from that of the conference presentation by Young et al., and did not involve interventional radiology to assist in removal of the self-inflicted soft tissue foreign bodies. Nonetheless, their discussion notes thatInsertion of foreign bodies is an unusual form of deliberate self-harm. Most are inserted through existing orifices, and urologists, ENT surgeons and gastrointestinal endoscopists may be involved in their assessment, monitoring and removal. Breach of an epithelium is less common, but is reported with insertion of long thin objects through the nose into the brain, or through the urethra and bladder into the abdominal cavity. Foreign bodies may also be inserted directly through skin, for example into the orbit, breast and abdomen. The forearm is a common site of deliberate self-harm by cutting, but our report is the first to highlight the forearm as a site for foreign body insertion.They also emphasize that medical management of these cases must take into account the underlying psychiatric problems, and ensure that the patients' emotional behavior doesn't compromise the standard of surgical care. The patients are often subject to stigmatization by health care providers, and psychiatry teams specializing in deliberate self-harm are recommended to improve the quality of care.So to conclude: "self-embedding disorder" is not a new phenomenon, just a new term for a variant of self-injurious behavior.Next on the agenda: Stay tuned for another [more egregiously] false press release from the RSNA...ReferenceW WRAIGHT, H BELCHER, H CRITCHLEY (2008). Deliberate self-harm by insertion of foreign bodies into the forearm. Journal of Plastic, Reconstructive & Aesthetic Surgery, 61 (6), 700-703 DOI: 10.1016/j.bjps.2007.04.004.... Read more »
W WRAIGHT, H BELCHER, & H CRITCHLEY. (2008) Deliberate self-harm by insertion of foreign bodies into the forearm. Journal of Plastic, Reconstructive , 61(6), 700-703. DOI: 10.1016/j.bjps.2007.04.004
...is the title of a book by Thea Hillman, in which (according to a review by David S. Hall),She speaks of her experiences as a young child, being diagnosed with Congenital Adrenal Hyperplasia, and what that experience meant to a four year old girl who was growing pubic hairs, a child who was poked and examined by many doctors, and had a total lack of personal privacy of her body. She comes back to this experience many times in the stories she tells of her life as a person who does not really know what gender she is.Congential Adrenal Hyperplasia (CAH) is an autosomal recessive genetic disorder that... is characterized by severe androgen excess beginning in the fetus. In about 95% of patients CAH is caused by a defect in the 21-hydroxylase gene (CYP21), leading to an impaired synthesis of cortisol ["stress hormone" produced by the adrenal gland] and aldosterone [hormone that causes the kidneys to retain sodium and water]. The low cortisol level triggers an increased production of adrenocorticotropic hormone, resulting in hyperplasia of the adrenal glands with increased synthesis of steroid precursors and elevation of androgen levels. The androgen excess is present from early embryogenesis, and causes in girls varying degrees of virilization of the external genitalia, depending on the degree of enzyme deficiency....as summarized in a new paper by Ciumas and colleagues (2008).In Intersex (for lack of a better word),[Hillman] speaks about her "outwardly simple though visually misleading, internally complicated gender."Ciumas et al. wanted to investigate whether fetal testosterone exposure is the major underlying mechanism for sexual dimorphism in the human brain. In particular, sex differences in the anatomy and physiology of the hypothalamus and the amygdala were of interest. Thus, they turned to adult women with CAH, sinceCertain rare conditions, so called experiments of nature, may here potentially offer unique information. A review of the literature suggested that some "sex-atypical" traits and behaviors may occur with CAH, but not all studies have agreed.Normal is a weapon of mass destruction.What is “normal”? Hall's review of Intersex continues:She speaks of her mother's prayers that she would be normal. She speaks of normal this way: "I take the war on terror personally because the war on terror is really a war on difference, because my body strikes terror in the hearts of other Americans. "My body and the bodies of the people I love are the most intimate sites of American imperialism. Because our sex anatomy isn't normal, they operate on us without our consent. Because who we have sex with isn't normal, they won't let us get married. Because our gender isn't normal, they don't give us jobs, health care, or housing. We work, we pay rent, we pay taxes, but because we're not normal, we don't get the same freedoms other Americans enjoy, the same freedoms American soldiers are murdering to protect."The study, which was not conducted in America but in Sweden by Dr. Ivanka Savic Berglund's group1 at the prestigious Karolinska Institute, was a continuation of their work on sex hormones and olfaction. Previously (Savic et al., 2001), they demonstrated that heterosexual men (HeM) and heterosexual women (HeW) showed different hypothalamic responses to smelling the putative pheromones, androstadienone (AND) and estratetraenol (EST). Specifically they used PET (positron emission tomography) to measure changes in cerebral blood flow responses to inhaling various odorants, which included sex steroids, butanol, cedar oil, lavender oil, and eugenol (clove). EST induced activity in the hypothalamus of HeM but in olfactory regions of HeW. Conversely, AND induced activity in the hypothalamus of HeW but in olfactory regions of HeM, which is not too surprising if these substances are, in fact, pheromones. The opposite sex pheromone is not processed like a regular scent, whereas the same sex pheromone is.Furthermore, they also examined hypothalamic responses to these putative pheromones in gay men (Savic et al., 2005) and lesbians (Berglund et al., 2006). In the first experiment, the comparison of gay men, straight men, and straight women was pretty straightforward (so to speak). HeM and HeW scored as 0 on the Kinsey scale (exclusively heterosexual), and the gay male subjects scored as 6 (exclusively homosexual). The results were as expected: the hypothalami of gay men were activated by AND, not EST (which was treated like any other odor). The results from the second experiment were less than straightforward. The lesbian group (between 5 and 6) did not look "just like straight men." Instead,...the lesbian subjects did not show a differentiated pattern of activation with AND and EST; they engaged the amygdala and the piriform and the insular cortices (the classical odor-processing circuits) when smelling both of these compounds.As a consolation prize, however, the lesbians were unlike HeW (since AND didn't turn on their hypothalami) and somewhat like HeM (since EST activated one overlapping region of the hypothalamus at a lower statistical threshold). [For more info on this study, see Sweat, Urine, and Sexual Orientation and The PNAS Word.]Note that I did not say anything about activity in specific hypothalamic nuclei [such as the so-called sexually dimorphic nucleus], because the PET method doesn't have the spatial resolution required to distinguish between them.That brings us to the present experiment. As you might guess, the question was whether CAH women looked more like HeM than HeW when sniffing the steroids.Is that what they found?Despite the genetically verified diagnosis and parental reports about boy-typical play behavior during childhood, the pattern of activation in the presently investigated CAH women was remarkably similar to that of female controls, and different from the pattern of male controls. CAH women and HeW activated the anterior hypothalamus with AND, whereas HeM activated this region with EST. Furthermore, whilst the amygdala connectivity differed between the male and female controls, no difference was observed between control females and CAH females. Thus, both with respect to aspects of functional organization and functional activation of the limbic circuits CAH women showed a pattern congruent with their biological sex, and different from the opposite sex. Our hypothesis that these specific aspects of cerebral dimorphism would have masculine features in CAH women was thereby rejected. So no, it was not what they found.Figure 1 (Ciumas et al., 2008). Illustration of group-specific activations with putative pheromones and odors. The Sokoloff's color scale illustrates Z values reflecting the degree of activation. As the same brain section is chosen, the figures do not always illustrate maximal activation for each condition. Clusters of activated regions are superimposed on the standard brain MRI, midsagittal plane.This failure to show a difference between CAH women and control women was obtained even though the two groups were not particularly well-matched for sexual orientation! [a glaring weakness that could have been rectified by recruiting a few bisexual control women]. Eight of the CAH women rated as Kinsey 0, but three others rated as 2, 4, and 5.2At any rate, these results provide no support for the notion that exposure to high levels of fetal testosterone will result in the "masculinization" of sexually dimorphic limbic circuits. Why? What does this have to say about fetal testosterone and the "male brain" view of development (e.g., Christine Knickmeyer & Baron-Cohen, 2006)? Ciumus et al. were puzzled, but offered the following speculations:Explanations to these discrepancies are not evident from the present data. We can only conclude that intrauterine virilization of genitalia is not necessarily paralleled by a masculinization of the limbic brain, at least not with respect to signal response to AND and EST, and the baseline amygdala connectivity, which are 2 indices of sex-dimorphism. It is theoretically possible that various sex dimorphic features are affected by fetal testosterone in a dose dependent manner. Whilst such a scenario could be attributed for the differences between HeM and HeW (with extremely high testosterone levels in male fetuses), it is less likely to explain the "male" like AND and EST activation and functional connectivity in lesbian women described in our previous studies. None of our lesbian participants in these studies had genital masculinization, which is expected already at moderate elevations of fetal testosterone. An alternative possibility is that various sex dimorphic features may have different etiological factors; in this respect recent studies by Arnolds group at UCLA are of particular interest as they indicate existence of early, and testosterone-independent chromosomal effects on the brain. Finally, several different etiological factors could contribute to a same sexually dimorphic cerebral feature, for example, psychosexual outcome. The 3 alternatives are not mutually exclusive. Although presently speculative, in the view of present results they all seem relevant to address in the near future. So there's no neat conclusion, only ambiguity. The calls for future studies are issued. But where does it all fit, in the grand scientific scheme of things? In the less grandiose human scale of things, to be different and yet not-so-different? When talking about her participation in the Intersex and Transgender communities, Thea Hillman says:"I fear that regardless of the fact that I've been hormonally altered since age six in order to achieve and maintain a mythical gender ideal, I can't safely talk about my concerns about hormones and surgery in our community for fear of being seen as anti-trans and anti-surgery."Footnotes1 In the recent past, The Neurocritic (and other neuropundits) have been critical of Savic's work on cerebral asymmetry and sexual orientation, but we'll put that aside for today.2 Another potential source of variability was the severity of the condition, which ranged from 1 to 5 (least to most severe), with a mean value of 3.18 in the 11 participants. Only four of the CAH women rated a severity of 4 or 5, so this might have obscured potential group differences in the data.ReferencesBerglund H, Lindström P, Savic I. (2006). Brain response to putative pheromones in lesbian women. Proc Natl Acad Sci. 103:8269-74.Christine Knickmeyer R, Baron-Cohen S. (2006). Fetal testosterone and sex differences. Early Hum Dev. 82:755-60.Savic I, Berglund H, Gulyas B, Roland P. (2001). Smelling of odorous sex hormone-like compounds causes sex-differentiated hypothalamic activations in humans. Neuron 31:661-8.Savic I, Berglund H, Lindström P. (2005). Brain response to putative pheromones in homosexual men. Proc Natl Acad Sci. 102:7356-61.C. Ciumas, A. L. Hirschberg, I. Savic (2008). High Fetal Testosterone and Sexually Dimorphic Cerebral Networks in Females. Cerebral Cortex DOI: 10.1093/cercor/bhn160.Active masculinization by fetal testosterone is believed to be a major factor behind sex differentiation of the brain. We tested this hypothesis in a 15O-H2O positron emission tomography study of 11 women with congenital adrenal hyperplasia (CAH), a condition with high fetal testosterone, and 26 controls. Two indices of cerebral dimorphism were measured—functional connectivity and cerebral activation by 2 putative pheromones (androstadienone [AND] and estratetraenol [EST]), previously reported to activate the hypothalamic networks in a sex-differentiated manner. Smelling of unscented air was the baseline condition, also used for measurements of functional connectivity from the amygdala. In CAH women and control women AND activated the anterior hypothalamus, and EST the amygdala, piriform, and anterior insular cortex. The pattern was reciprocal in the male controls. Also the functional connections were similar in CAH women and control women, but different in control men. Women displayed connections with the contralateral amygdala, cingulate, and the hypothalamus, men with the basal ganglia, the insular and the sensorimotor cortex. Furthermore, the connections were in CAH and control women more widespread from the left amygdala, in men from the right amygdala. Thus, we find no evidence for masculinization of the limbic circuits in women with high fetal testosterone."Normal is a weapon of mass destruction.It's just as deadly, and just like those weapons,it'll never be found."-Thea Hillman, writer and intersex activist... Read more »
C. Ciumas, A. L. Hirschberg, & I. Savic. (2008) High Fetal Testosterone and Sexually Dimorphic Cerebral Networks in Females. Cerebral Cortex. DOI: 10.1093/cercor/bhn160
Figure 1 (Ruocco et al., 2006). Samples of coronal and sagittal magnetic resonance imaging from a patient with Huntington's disease (top row) and a normal control (bottom row) showing the outlines of caudate and putamen (left), cerebral (center) and cerebellar volumes (right).Huntington's disease is an inherited, autosomal dominant, neurodegenerative disorder. Although primarily viewed as a movement disorder characterized by uncontrollable body movements (chorea), there is also a marked decline in cognitive abilities, often accompanied by psychiatric issues as well.
It's a terrible disease that typically onsets in middle age. A heartbreaking New York Times article, Facing Life With a Lethal Gene, follows a 23 year old woman who decides to get tested and finds out she carries the gene. Her grandfather had the disease, meaning that her mother, who did not know her own genetic status, was doomed to develop HD.As stated in this Lancet review article (Walker, 2007),The mutant protein in Huntington’s disease—huntingtin—results from an expanded CAG repeat leading to a polyglutamine strand of variable length at the N-terminus. Evidence suggests that this tail confers a toxic gain of function.The defective protein causes cell death in various brain regions, particularly in the striatum (caudate and putamen), perhaps due to an excitotoxic mechanism (Sánchez et al., 2008). As Beste et al. (2008) explain in their new J Neurosci paper,Excitotoxicity describes cell death that results from the activation of excitatory amino acid receptors. In HD, voltage-dependent NMDA receptors are assumed to be more receptive to endogenous levels of glutamate; thus glutamatergic neurotransmission is increased, leading to excitotoxic cell death. The medium spiny neurons in the striatum are especially affected. Given all this neurodegeneration and the concomitant decline in motor function and cognition, it was surprising to see a paper reporting an enhanced perceptual/cognitive ability. But that's what Beste et al. (2008) observed. In their study, patients with HD, pre-symptomatic carriers, and controls participated in an auditory processing experiment while EEG data were recorded. The task consisted of categorizing the duration of pure tones as either long (400 ms) or short (200 ms). The tones were of different frequencies and different probabilities, but this was irrelevant to the task. This difference in probability, however, results in different patterns of brain waves to the common ("standard") and rare ("deviant") tones. Specifically, the authors looked at the mismatch negativity (MMN) component associated with auditory sensory memory, and the P3a component associated with attention. These waves were derived by averaging together many trials of the task, which produces event-related potentials (ERPs).Behaviorally speaking, the participants with HD were faster and more accurate on the auditory task.Figure 1 (Beste et al., 2008). Behavioral data. A, Mean reaction time (error bars indicate SEM) of the control, the presymptomatic (pHD), and the symptomatic (HD) group for the standard and deviant stimuli. B, Mean error rates (error bars indicate SEM) of the control, the presymptomatic (pHD), and the symptomatic (HD) group for the standard and deviant stimuli.For the ERPs, responses to the standard tones were subtracted from responses to the deviant tones, producing a so-called "difference wave." The MMN can be seen between 100-250 ms after stimulus presentation and the P3a can be seen between 300 and 500 ms post-stimulus. A later wave (the reorienting negativity, or "RON") was seen between 400 and 600 ms.adapted from Figure 2 (Beste et al., 2008). Neurophysiological data (difference waves). For all electrodes shown, the time course from 200 ms before tone onset until 1100 ms beyond tone presentation is given. Red lines denote the ERP time course of the HD group, orange lines of the pHD group, and green lines of the control group. The HD group showed a significant increase in MMN compared to the pHD and control groups. On the other hand, although the P3a looked smaller in HD participants, the difference was not significant. The later RON wave was enhanced in the HD group, however. The authors suggest:The results show that specific cognitive functions, namely auditory sensory memory (reflected by the MMN) and reorientation of attention (reflected by the RON) are not deteriorated and can even be enhanced in late stage HD. Moreover, the results suggest that superiority in these functions emerge primal in the late stage of this disease, because pHDs performed worse. I should point out that on nearly every other neuropsychological test (i.e., word fluency, digit span, Stroop interference, immediate and delayed memory), the subjects with HD were extremely impaired. Then what is the mechanism for the enhancement of auditory abilities?...the specific dependence of the MMN on the corticostriatal NMDA system underlies this dissociation of performance in HD as well as the enhancement and acceleration of the MMN. The NMDA-receptor system has been found to modulate the MMN (Javitt et al., 1996).. . .The observation that the reorientation of attention (reflected by the RON) was also increased in the HD group accords with the enhanced behavioral performance in the relevant task... Although the primary effects of neurodegenerative diseases like HD might be largely confined to certain cell populations in restricted areas of the brain, these changes can affect cognitive and motor systems at multiple levels of the brain. In most cases, the pathological alterations of neural systems result in a deterioration of cognitive functions. However, as shown in the present study, a pathogenic increase in responsiveness of a transmitter system can increase cognitive functions if these functions selectively depend on this neural system, whereas other cognitive functions are deteriorated. What is the clinical relevance of this finding? It's not clear. But the results revealed an unexpected and striking dissociation of cognitive abilities in patients with Huntington's disease.ReferencesC. Beste, C. Saft, O. Gunturkun, M. Falkenstein (2008). Increased Cognitive Functioning in Symptomatic Huntington's Disease As Revealed by Behavioral and Event-Related Potential Indices of Auditory Sensory Memory and Attention. Journal of Neuroscience, 28 (45), 11695-11702 DOI: 10.1523/JNEUROSCI.2659-08.2008Estrada Sánchez AM, Mejía-Toiber J, Massieu L. (2008). Excitotoxic neuronal death and the pathogenesis of Huntington's disease. Arch Med Res. 39:265-76.Javitt DC, Steinschneider M, Schroeder CE, Arezzo JC. (1996). Role of cortical N-methyl-D-aspartate receptors in auditory sensory memory and mismatch negativity generation: Implications for schizophrenia. Proc Natl Acad Sci. 93:11962–11967.H.H. Ruocco, I. Lopes-Cendes, L.M. Li, M. Santos-Silva, F. Cendes. (2006). Striatal and extrastriatal atrophy in Huntington’s disease and its relationship with length of the CAG repeat. Braz J Med Biol Res. 39: 1129-1136.Walker FO. (2007). Huntington's disease. Lancet 369:218-28.... Read more »
C. Beste, C. Saft, O. Gunturkun, & M. Falkenstein. (2008) Increased Cognitive Functioning in Symptomatic Huntington's Disease As Revealed by Behavioral and Event-Related Potential Indices of Auditory Sensory Memory and Attention. Journal of Neuroscience, 28(45), 11695-11702. DOI: 10.1523/JNEUROSCI.2659-08.2008
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